RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: Johnny has 4 classes. He averaged a mark of 83 in those classes. If Johnny takes night school and scores an 88 in the course, what will his new average be?
A.83
B.84
C.85
D.85.5
Answer: B.84
Explanation: (sum of the 4 marks)/4 = 83
sum of the 4 marks = 332
new sum = 332 + 88 = 420
new average = 420/5 = 84
ans: B
Question: A student chose a number, multiplied it by 7, then subtracted 150 from the result and got 130. What was the number he chose?
A.40
B.42
C.44
D.46
Answer: A.40
Explanation: Let x be the number he chose, then
7⋅x−150=130
7x=280
x=40
correct answer A
Question: The surface area of a cube is 1734 sq. cm. Find its volume
A.2334 cubic.cm
B.3356 cubic.cm
C.4913 cubic.cm
D.3478 cubic.cm
Answer: C.4913 cubic.cm
Explanation: Explanation:
Let the edge of the cube bea. Then,
6a2 = 1734
=> a = 17 cm.
Volume = a3 = 173 = 4193 cm3
Answer: C
Question: A certain pilot flew 400 miles to City K at an average speed of 350 miles per hour with the wind and made the trip back at an average speed of 150 miles per hour against the wind. Which of the following is closest to the pilot’s average speed, in miles per hour, for the round-trip?
A.280
B.210
C.300
D.310
Answer: B.210
Explanation: Avg speed = total distance/ total time
total distance = 800
total time = 400/350 + 400/150 = 80/21
=> avg speed = (800*21)/80 = 210(approx)
ans is B
Question: The average of 11 numbers is 10.6. If the average of the first six numbers is 10.5 and that of the last six numbers is 11.4, then the middle number is
A.71.5
B.11.5
C.81.5
D.14.8
Answer: D.14.8
Explanation: Explanation:
Middle numbers = [(10.5 x 6 + 11.4 x 6) - 10.6 x 11] = 14.8.
Answer: D
Question: A toy store regularly sells all stock at a discount of 10 percent. If an additional 10 percent were deducted from the discount price during a special sale, what would be the lowest possible price of a toy costing $10 before any discount?
A. $7.20
B. $8.00
C. $8.10
D. $8.27
Answer: C. $8.10
Explanation: sale price = (original price - 10% decrease) - 10% decrease
price = [10 * (90/100)] * (90/100) = 10 * (.90) * (.90) = 9 * .90 = 8.10
The answer is C.
Question: A merchant gains or loses, in a bargain, a certain sum. In a second bargain, he gains 680 dollars, and, in a third, loses 80. In the end he finds he has gained 250 dollars, by the three together. How much did he gain or lose bv the first ?
A.-280
B.300
C.-350
D.-380
Answer: C.-350
Explanation: In this sum, as the profit and loss are opposite in their nature, they must be distinguished by contrary signs. If the profit is marked +, the loss must be -.
Let x = the sum required.
Then according to the statement x + 680 - 80 = 250
And x = -350.
Answer C
Question: In a certain store, the profit is 320% of the cost. If the cost increases by 25% but the selling price remains constant, approximately what percentage of the selling price is the profit?
A.30%
B.70 percent
C.100%
D.120%
Answer: B.70 percent
Explanation: Solution
Let C.P. = Rs. 100.	Then, Profit = Rs.320,
S.P. = 420.
Let C.P. = Rs. 125% of Rs. 100	= Rs.125.
New S.P. = Rs.420.
Profit = Rs. (420 - 125)	= Rs.295.
∴ Required percentage	= (295 / 420 x 100)%
= 1475 / 21%
= 70%.
Answer B
Question: 6+3+2 = 242116
8+9+1 = 727216
5+7+4 = 505644
2+7+5 =?
A.224210
B.224220
C.224230
D.224240
Answer: D.224240
Explanation: 6+3+2 = 242116 = 6*(3+2-1) 3*(6+2-1) 2*(6+3-1)=6*4 3*7 2*8= 242116
8+9+1 = 727216
5+7+4 = 505644 = (5*10) (7*8) (4*11)
2+7+5 = 2*(7+5-1) 7*(2+5-1) 5*(2+7-1) = 224240
ANSWER:D
Question: The ratio 25:50 expressed as percent equals to
A.50 %
B.85 %
C.25 %
D.75 %
Answer: A.50 %
Explanation: Explanation:
Actually it means 25 is what percent of 50, which can be calculated as,
(25/50)*100 = 25 * 2 = 50
Answer: Option A
Question: Find the C.I. on a sum of Rs.10000 for 6 months at 25% per annum, interest being compounded quarterly?
A.10290
B.5290
C.1289
D.1290
Answer: C.1289
Explanation: C.I.= 2000(21/20)^2-1800
= 1289
Answer: C
Question: If pqr < 0 and qr > 0, which of the following must be positive?
A. xy
B. xz
C. (p^2)qr
D. p(q^2)r
Answer: C. (p^2)qr
Explanation: Given that qr is positive and pqr is negative, you can say that p MUST be negative. As for q and r either they are both positive or both negative.
Option (C) has p^2 which is positive and qr which is positive. So (C) must be positive.
Question: 56 +57+58+59=230. How many such 4 consecutive numbers are there less than 500 when added gives a sum which is divisible by 10?
A.100
B.200
C.300
D.400
Answer: A.100
Explanation: since 1+2+3+4=10 & 6+7+8+9=30
any combination with these no be will give u desirable result...
so total no in 100 will be 20 & that's why in in 500,it will be 20x5=100.
ANSWER:A
Question: Consider a quarter of a circle of radius 36. Let r be the radius of the circle inscribed in this quarter of a circle. Find r.
A.16*(sqr2 -1)
B.8*(sqr3 -1)
C.4*(sqr7 - 1)
D.36* (sqr2 -1)
Answer: D.36* (sqr2 -1)
Explanation: I got 36/(sqr2 +1) and just forgot to multiply by (sqr2 -1).
Answer is D
Question: In how many ways can 8 Indians and, 4 American and 4 Englishmen can be seated in a row so that all person of the same nationality sit together?
A.3!*8!*4!*4! ways
B.8!*4!*4! ways
C.3!4! ways
D.3!*5! ways
Answer: A.3!*8!*4!*4! ways
Explanation: Taking all person of same nationality as one person, then we will have only three people.
These three person can be arranged themselves in 3! Ways.
8 Indians can be arranged themselves in 8! Way.
4 American can be arranged themselves in 4! Ways.
4 Englishman can be arranged themselves in 4! Ways.
Hence, required number of ways = 3!*8!*4!*4! Ways.
ANSWER A
Question: Dan's age after 16 years will be 4 times his age 8 years ago. What is the present age of Dan?
A.12
B.16
C.20
D.24
Answer: B.16
Explanation: Let Dan's present age be x.
x+16 = 4(x-8)
3x = 48
x = 16
The answer is B.
Question: A train covers a distance of 18 km in 10 min. If it takes 6 sec to pass a telegraph post, then the length of the train is?
A.120m
B.180m
C.240m
D.220m
Answer: B.180m
Explanation: Speed = (18/10 * 60) km/hr = (108 * 5/18) m/sec = 30 m/sec.
Length of the train = 30 * 6 = 180 m.
ANSWER:B
Question: Use distributive property to solve the problem below:
Maria bought 10 notebooks and 5 pens costing 3 dollars each.How much did Maria pay?
A.30 dollars
B.40 dollars
C.45 dollars
D.60 dollars
Answer: C.45 dollars
Explanation: Solution
3 × (10 + 5) = 3 × 10 + 3 × 5 = 30 + 15 = 45 dollars
Answer C
Question: The present ages of three persons in proportions 4 : 7 : 5. Eight years ago, the sum of their ages was 56. Find their present ages (in years).
A.8, 20, 28
B.16, 28, 36
C.20, 35, 25
D.16, 28, 34
Answer: C.20, 35, 25
Explanation: Let their present ages be 4x, 7x and 5x years respectively.
Then, (4x - 8) + (7x - 8) + (5x - 8) = 56
16x = 5.
Their present ages are 4x = 20 years, 7x = 35 years and 5x = 25 years respectively.
Answer:C
Question: Jackson has $313,192 dollars in his investment accounts. What is the least amount of money (in whole number of dollars) that he must remove from his account if he wants to split this money evenly among nine new investors?
A.$1
B.$2
C.$3
D.$4
Answer: A.$1
Explanation: In order to divide the sum in 9 parts, the amount must also be divisible by 9
Divisibility rule of 9: The sum of the digits must be divisible by 9
Sum of digits of 313,192 = 19 and 18 is divisible by 9.
Hence we need to subtract 1 to this number for it to be divisible by 9
Correct Option: A
Question: A man takes twice as long to row a distance against the stream as to row the same distance in favour of the stream. The ratio of the speed of the boat(in still water) and the stream is
A.1:2
B.1:3
C.2:1
D.3:1
Answer: D.3:1
Explanation: Sol.
Let man’s rate upstream be x kmph. Then, his rate downstream = 2x kmph.
∴ (Speed in still water) : (Speed of stream)
= [2x + x / 2] : [2x - x / 2]
3x / 2 : x / 2 = 3:1.
Answer D
Question: How many words can be formed by using all letters of word ALIVE.
A.120
B.236
C.128
D.261
Answer: A.120
Explanation: Explanation:
The word ALIVE contains 5 different letters
Therefore,
Required number of words = 5p5 = 5!
= (5*4*3*2*1) = 120
ANSWER:A
Question: one person Tharak speed with the current is 10 km/hr and the speed of the current is 4 km/hr. Tharak's speed against the current is:
A.0 km/hr
B.1 km/hr
C.2 km/hr
D.3 km/hr
Answer: C.2 km/hr
Explanation: Man's speed with the current = 10 km/hr
=> speed of the man + speed of the current = 10 km/hr
speed of the current is 4 km/hr
Hence, speed of the man = 10-4 = 6 km/hr
man's speed against the current = speed of the man - speed of the current
= 6-4 = 2 km/hr
ANSWER:C
Question: A shopkeeper sells two articles at Rs.1000 each, making a profit of 20% on the first article and a loss of 20% on the second article. Find the net profit or loss that he makes?
A.8%
B.2%
C.3%
D.4%
Answer: D.4%
Explanation: SP of first article = 1000
Profit = 20%
CP = (SP)*[100/(100+P)] = 5000/6 = 2500/3
SP of second article = 1000
Loss = 20%
CP = (SP)*[100/(100-L)] = 5000/4 = 1250
Total SP = 2000
Total CP = 2500/3 + 1250 = 6250/3
CP is more than SP, he makes a loss.
Loss = CP-SP = (6250/3)- 2000 = 250/3
Loss Percent = [(250/3)/(6250/3)]*100
=0.04 * 100
= 4%
Answer:D
Question: The smallest number when increased by " 1 " is exactly divisible by 6,18,36,48, 60 is:
A.724
B.721
C.720
D.719
Answer: D.719
Explanation: LCM = 720
720 - 1 = 719
ANSWER:D
Question: A cyclist traveled for two days. On the second day the cyclist traveled 3 hours longer and at an average speed 10 mile per hour slower than she traveled on the first day. If during the two days she traveled a total of 280 miles and spent a total of 12 hours traveling, what was her average speed on the second day?
A.5 mph
B.10 mph
C.20 mph
D.30 mph
Answer: B.10 mph
Explanation: SOLUTION:
D = 280 Mi
T = 12 hrs
Day 1 time = T1
Day 2 time = T2
T2 - T1 = 4 hrs ----- (I)
T1 + T2 = 12 hrs ----- (II)
Adding I and II, T2 = 8 hrs and T1 = 4 hrs
Day 1 Rate = R1
Day 2 Rate = R2
R1 - R2 = 10 mph
i.e. R1 = 10 + R2
280 = 8R2 + 4R1
i.e. 280 = 8R2 + 4 (10 + R2)
i.e. R2 = 20 mph
ANSWER: B
Question: In a group of hats consisting of only blue hats, green hats, and purple hats, the ratio of blue hats to green hats to purple hats is 7:4:12. If there are a total of 161 hats in this group, how many of these hats are not blue?
A.28
B.42
C.48
D.112
Answer: D.112
Explanation: Since the hats Blue, Green and Purple are in ratio of 7:4:12...The total no. of balls will be
7x+4x+12x=161 or 23x=161...here 7x,4x and 12x represent hats of each type
23x=161 so x=7...Blue hats =7*7=49...Not blue will be 161-49=112.
Ans D
Question: By selling an article at Rs.600, a profit of 25% is made. Find its cost price?
A.288
B.992
C.678
D.480
Answer: D.480
Explanation: SP = 600
CP = (SP)*[100/(100+P)]
= 600 * [100/(100+25)]
= 600 * [100/125] = Rs.480
Answer:D
Question: A person can swim in still water at 4 km/h. If the speed of water 2 km/h, how many hours will the man take to swim back against the current for 6km?
A.3
B.6
C.7
D.8
Answer: A.3
Explanation: M = 4
S = 2
US = 4 - 2 = 2
D = 6
T = 6/2 = 3
Answer: A
Question: X starts a business with Rs.45000. Y joins in the business after 3 months with Rs.30000. What will be the ratio in which they should share the profit at the end of the year?
A.1:2
B.1:3
C.2:1
D.1:4
Answer: C.2:1
Explanation: Ratio in which they should share the profit
= Ratio of the investments multiplied by the time period
=45000×12:30000×9
=45×12:30×9
=3×12:2×9
=2:1
Answer is C.
Question: 54.327 × 357.2 × 0.0057 is the same as :
A.5.4327 × 3.572 × 5.7
B.5.4327 × 3.572 × 0.57
C.5.4327 × 3.572 × 0.0000057
D.None of these
Answer: A.5.4327 × 3.572 × 5.7
Explanation: Solution
Number of Decimal places in the given expression =8 .
Number of Decimal places in (a) = 8 .
Number of Decimal places in (b) =9 .
Number of Decimal places in (c) = 7 .
Number of Decimal places in (a) is the same as the given expression . Answer A
Question: If 100<x<190 and 10<y<100, then the product xy CANNOT be equal to:
A.18,104
B.18,303
C.18,356.732
D.19,502
Answer: D.19,502
Explanation: Correct Answer: (D)
Determine the range of xy by multiplying the two extremes of each individual range together. The smallest value of xy must be greater than 100 * 10. The largest value must be less than 190 * 100. This means that 1000 < xy < 19,000. (D) is outside of this range, so it is not a possible product of xy.
Question: A teacher prepares a test. She gives 6 objective type questions out of which 4 have to be answered. Find the total ways in which they can be answered if the first 3 questions have 3 choices and the last 3 have 4 choices.
A.255
B.1816
C.1872
D.100
Answer: C.1872
Explanation: Two cases.
First Case: 2 Questions - 3 Choices, 2 Questions - 4 Choices
3C2 * 3C2 ways to select the questions
3C1 * 3C1 * 4C1 * 4C1 ways to answer the questions
= 3 * 3 * 3 * 3 * 4 * 4
=1296
Second Case: 1 Question - 3 Choices, 3 Questions - 4 Choices
3C1 * 3C3 ways to select the questions
3C1 * 4C1 * 4C1 * 4C1 ways to answer the questions
= 3 * 1 * 3 * 4 * 4 * 4
= 576
Total = 1296 + 576
= 1872
C
Question: Find 356 x 936 - 356 x 836 = ?
A.35600
B.34500
C.49630
D.93600
Answer: A.35600
Explanation: Answer
356 x 936 - 356 x 836 = 356 x (936 - 836 )
= 356 x 100
= 35600.
Option: A
Question: 7 chess players take part in a tournament. Every player plays twice with each of his opponents. How many games are to be played?
A.40
B.48
C.45
D.42
Answer: D.42
Explanation: Though 2*(7C2) is the correct approcah to do this, but for people like me who find Perm, Comb n Prob a nightmare, an easy approach can be used.
The first guy has to play 2 matches with the rest of 6, so he'll play 12matches.
Similarly, second guy has to play with the rest of 5 as his 2 games with the first guy are already played. So he plays 10 matches.
This continues like this and the total matches are 12+10+8...+2
12+10+...+2 = 2(6+5+...+1) = 2((6*7)/2) = 6*7 =42.
ANSWER:D
Question: P can do a certain work in 16 days. Q is 60% more efficient than P. How many days does Q alone take to do the same job?
A.8
B.9
C.10
D.11
Answer: C.10
Explanation: Each day, P can do 1/16 of the work.
Each day, Q can do 1.6/16 of the work = 16/160 of the work
The time taken by B alone to complete the total work is 160/16 = 10 days.
The answer is C.
Question: A can do a piece of work in 15 days and B in 20 days. They began the work together but 5 days before the completion of the work, A leaves. The work was completed in?
A.11 3/9
B.19 3/7
C.11 3/5
D.11 3/7
Answer: D.11 3/7
Explanation: (x – 5)/15 + x/20 = 1
x = 11 3/7 days
Answer:D
Question: If KING is coded as 17 and MASS is coded as 29 Then DON is coded as
A.21
B.20
C.18
D.16
Answer: C.18
Explanation: KING = 11+9+14+7=41 i.e (4*4)+(1*1)=17
MASS = 13+1+19+19=52 i.e (5*5)+(2*2)=29
DON = 4+14+15=33 i.e(3*3)+(3*3)=18
ANSWER:C
Question: In March, Kurt ran an average of 1.2 miles an hour. If by June he had increased his pace by 20 seconds per mile, then which of the following expresses the number of hours it would take Kurt to complete one mile in June?
A.3590/60^2
B.2980/60^2
C.2390/60^2
D.3586/60
Answer: B.2980/60^2
Explanation: Kurt ran at an average of 1.2 miles/hour in march. So to run 1 mile he would take 1/1.2 hours = (60 * 60)/1.2 seconds = 3000 seconds.
If he increases his speed by 20 seconds, he will complete a mile in 2980 seconds. Converting in hours = 2980/(60 * 60) = 2980/(60^2)
ANSWER: B
Question: A distributor sells a product through an online store, which take a commission of 20% of the price set by the distributor. The distributor obtains the product from a producer at the price of $19 per item. What is the price that the buyer observers online if the distributor wants to maintain a 20% profit on the cost of the item?
A.$27.50
B.$28.50
C.$29.50
D.$30.50
Answer: B.$28.50
Explanation: Let x be the price that buyers see online.
The distributor wants to receive 1.2(original price) which should be 80% of x.
1.2(19) = 0.8x
x = 1.2(19) / 0.8 = 1.5(19) = $28.50
The answer is B.
Question: A person takes 5 hrs 45 min in walking to a place and riding back. He would have gained 4 hrs by riding both ways. The time he would take to walk both ways is?
A.5 hours 45 min
B.5 hours 55 min
C.6 hours 45 min
D.9 hours 45 min
Answer: D.9 hours 45 min
Explanation: ----------------------------------------------------------------
Solution 1
----------------------------------------------------------------
Given that time taken for riding both ways will be 4 hours lesser than
the time needed for waking one way and riding back
From this, we can understand that
time needed for riding one way = time needed for waking one way - 4 hours
Given that time taken in walking one way and riding back = 5 hours 45 min
Hence The time he would take to walk both ways = 5 hours 45 min + 4 hours = 9 hours 45 min
D
Question: Find the area of a parallelogram with base 12 cm and height 8 cm?
A.96 cm2
B.104 cm2
C.78 cm2
D.86 cm2
Answer: A.96 cm2
Explanation: Area of a parallelogram = base * height = 12 * 8
= 96 cm2
Answer:A
Question: In a bag, there are coins of 25 p, 10 p and 5 p in the ratio of 1 : 2 : 3. If there is Rs. 30 in all, how many 25 p coins are there?
A.20
B.30
C.25
D.50
Answer: D.50
Explanation: Let the number of 25 p, 10 p and 5 p coins be x, 2x, 3x respectively.
Then, sum of their values = (25 x/100) + (20 x/100) + (15 x/100)
= 60 x /100
30 = 60 x / 100
x = 50 = 25 p coin
Ans - D
Question: A train 200 m long is running at the speed of 30 km / hr. Find the time taken by it to pass a man standing near the railway line in seconds
A.12 sec
B.6 sec
C.7 sec
D.8 sec
Answer: A.12 sec
Explanation: Explanation:
Speed of the train = (60 x 5/18m / sec = 50/3 m/ sec.
Distance moved in passing the standing man = 100 m.
Required time taken = 200/(50/3) = (200 Ã—(3/50)) sec =12 sec
Answer: Option A
Question: In a store, the profit is 320% of the cost. If the cost increases by 25% but the SP remains constant, approximately what %of the sp is the profit?
A.50%
B.70%
C.90%
D.100%
Answer: B.70%
Explanation: Let C.P. = Rs. 100. Then, profit = Rs. 320, S.P. = Rs. 420
New C.P. = 125% of Rs. 100 = Rs. 125.
New S.P. = Rs. 420
Profit = 420 - 125 = Rs. 295
Required percentage = 295/420 * 100 = 1475/21 = 70%
B
Question: If a - b = 5 and a2 + b2 = 29, find the value of ab.
A.A)2
B.B)12
C.C)15
D.D)18
Answer: A.A)2
Explanation: Explanation:
2ab = (a2 + b2) - (a - b)2
= 29 - 25 = 4
ab = 2.
Answer: A
Question: The average age of a husband and his wife was 23 years at the time of their marriage. After five years they have a one year old child. What is the average age of the family ?
A.21 years
B.20 years
C.18 years
D.19 years
Answer: D.19 years
Explanation: after 5 years the average age of the two will be 28.
now the child is one year old ,
total age = 28*2 + 1 = 57
average age = total age/family members(3)
=> 57/3 = 19
ANSWER:D
Question: If n = 8^8 – 7, what is the units digit of n?
A.0
B.1
C.2
D.7
Answer: D.7
Explanation: 8 ^ 8 - 8 = 8 (8 ^ 7 - 1)
==> 8 (2 ^ 21 - 1)
Last digit of 2 ^ 21 is 2 based on what explanation LiveStronger is saying. 2 ^ 24 - 1 yields 2 - 1 = 1 as the unit digit. Now on multiply this with 7, we get unit digit as 7
Answer : D
Question: Which of the following describes all values of x for which 36–x^2 >= 0?
A. x >= 1
B. x <= –1
C. -6 <= x <= 6
D. x <= –1 or x >= 1
Answer: C. -6 <= x <= 6
Explanation: 36 - x^2 >=0
means x^2 - 36 <=0
=> (x-6)(x+6) <= 0
=> -6 <= x <= 6
Answer - C
Question: In a certain accounting class of 100 students, 70% of the students took the final exam on the assigned day while the rest of the students took the exam on a make-up date. If the students on the assigned day had an average score of 55%, and the students on the make-up date had an average score of 95%, what was the average score for the entire class?
A.60%
B.65%
C.67%
D.70%
Answer: C.67%
Explanation: 70% of the class scored 55% and 30% of the class scored 95%.
The difference between 55% and 95% is 40%.
The average will be 55% + 0.3(40%) = 67%.
The answer is C.
Question: If 15 men, working 9 hours a day, can reap a field in 16 days, in how many days will 18 men reap the field, working 8 hours a day?
A.10
B.15
C.20
D.25
Answer: B.15
Explanation: Let the required number of days be x.
More men, Less days (indirect proportion)
Less hours per day, More days (indirect proportion)
Men 18 : 15
Hours per day 8: 9 } : :16 : x
(18 x 8 x x)=(15 x 9 x 16)= x=(44 x 15)144 = 15
Hence, required number of days = 15.
Answer is B.
Question: 10% of inhabitants of a village having died of cholera, a panic set in, during which 25% of the remaining inhabitants let the village. The population is then reduced to 4050. Find the original inhabitants
A.5500
B.6000
C.6500
D.7000
Answer: B.6000
Explanation: Explanation:
Let the total number is x,
then,
(100-25)% of (100 - 10)% x = 4050
=> 75% of 90% of x = 4050
=> 75/100 * 90/100 * x = 4050
=> x = (4050*50)/27 = 6000
Answer: Option B
Question: The average age of 15 students of a class is 15 years. Out of these, the average age of 5 students is 14 years and that of the other 9 students is 16 years. The age of the 15th student is?
A.9
B.11
C.15
D.12
Answer: B.11
Explanation: Age of the 15th student = 15*15 - (14*5+16*9) = 225-214 = 11 years
Answer is B
Question: Which of the following is a multiply of 4 number ?
A.120
B.130
C.45
D.82
Answer: A.120
Explanation: Explanation :
120 is a perfect multiply of 4
Answer : Option A
Question: There is a group of persons each of whom can completea piece of work in 16 days, when they are working individually. On the 1st day 1 person works, on the second day another person joins him, on the third day one more person joins them & this process continues till the work is completed. How many days are needed to complete the work?
A.5 1⁄2 days
B.5 1⁄3 days
C.5 1⁄6 days
D.6 1⁄6 days
Answer: C.5 1⁄6 days
Explanation: Work completed in 1st day = 1/16
Work completed in 2nd day = (1/16) + (1/16) = 2/16
Work completed in 3rd day = (1/16) + (1/16) + (1/16) = 3/16
…
An easy way to attack such problems is from the choices. You can see the choices are
very close to each other. So just see one by one.
For instance, The first choice given in 3 1⁄4
The work done in 3 days = 1/16 + 2/16 + 3/16 = (1+2+3)/16 = 6/16
The work done in 4 days = (1+2+3+4)/16 = 10/16
The work done in 5 days = (1+2+3+4+5)/16 = 15/16, almost close, isn't it?
The work done in 6 days = (1+2+3+4+5+6)/16 > 1
Hence the answer is less than 6, but greater than 5. Hence the answer is 5 1⁄6 days.
(Just for your reference, work done in 5 days = 15/16.
Pending work in 6th day = 1 – 15/16 = 1/16.
In 6th day, 6 people are working and work done = 6/16.
To complete the work 1/16, time required = (1/16) / (6/16) = 1/6 days.
Hence total time required = 5 + 1/6 = 5 1⁄6 days
C
Question: What is the units digit of 6^m(2^7+1), for a positive integer m?
A.1
B.3
C.4
D.7
Answer: C.4
Explanation: Equation can be re-written as
6^m( 2^7 + 1)
=6^m ( 128 + 1)
=6^m (129)
Now, putting m= 0 ; Eqn = 129
putting m= 1 ; Eqn = 129. 6
putting m= 2 ; Eqn = 129 .36
putting m= 3 ; Eqn = 129 .216
We can see that there lies a pattern while multiplying 129 with multiples of 6 , units digit is always going to be 4
ANSWER:C
Question: Bill has a collection of new and used trading cards that he stores in two albums. His first album contains 200 cards, 60% of which are used. If 90% of the cards in his second album are used, and 65% of all of his cards are used, what is the total number of trading cards in Bill’s collection?
A.290
B.260
C.254
D.240
Answer: D.240
Explanation: Let, Total Cards in second collection = B
(60/100)*200 + (90/100)*B = (65/100)*(200+B)
i.e. B = 40
i.e Total cards = 200+B = 240
Answer: OPtion D
Question: Arun and Tarun can do a work in 10 days.After 4 days tarun went to his village.How many days are required to complete the remaining work by Arun alone.Arun can do the work alone in 20 days.
A.12 days.
B.17 days.
C.18 days.
D.19 days.
Answer: A.12 days.
Explanation: They together completed 4/10 work in 4 days.
balance 6/10 work will be completed by Arun alone in 20*6/10 = 12 days.
ANSWER:A
Question: 9, 35, 91, 189, 341, ?
A.502
B.521
C.559
D.611
Answer: C.559
Explanation: Explanation :
13 + 23 = 9
23 + 33 = 35
33 + 43 = 91
43 + 53 = 189
53 + 63 = 341
63 + 73 = 559
Answer : Option C