RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: Two members of a club are to be selected to represent the club at a national meeting. if there are 120 different possible selections of the 2 members, how many members does the club have?
A.20
B.27
C.16
D.57
Answer: C.16
Explanation: I have done this problem by substituting numbers
We have n!/2!(n-2)! = 120
or n(n-1)/2 = 120 or n^2-n =240 or (n-16)(n+15)
n=16 satisfies the equation
C
Question: If x = 8 and y = −2, what is the value of (x − 2y)^y?
A.−100
B.0.007
C.0.25
D.4
Answer: B.0.007
Explanation: Quickly we can spot that answer is neither integer nor negative. Eliminate A, DE
by inversing and squaring 0.007
Answer: B
Question: When 12 + 10 = 1205, 11 + 8 = 885, then 16 + 15 = ?
A.2405
B.3205
C.2463
D.2631
Answer: A.2405
Explanation: A
2405
12 + 10 => 12 × 10 = 120 => 120 × 10 + 5 = 1205
11 + 8 => 11 × 8 = 88 => 88 × 10 + 5 = 885
16 + 15 => 16 × 15 = 240 => 240 × 10 + 5 = 2405
Question: You have a bag of 9 letters: 3 Xs, 3 Ys and 3 Zs. You are given a box divided into 3 rows and 3 columns for a total of 9 areas. How many different Y ways can you place one letter into each area such that there are no rows or columns with 2 or more of the same letter?
A.5
B.6
C.9
D.12
Answer: D.12
Explanation: Consider one particular arrangement of the first row: XYZ, then we can construct only two boxes with so that no rows or columns have 2 or more of the same letter:
XYZ
YZX
ZXY
And:
XYZ
ZXY
YZX
Now, the first row itself can be arranged in 3!=6 ways (since there are three distinct letter), hence the total number of boxes possible Y is 2*6=12.
Answer: D.
Question: Ron walks to a viewpoint and returns to the starting point by his car and thus takes a total time of 6 hours 45 minutes. He would have gained 2 hours by driving both ways. How long Q would it have taken for him to walk both ways.
A.8 h 45 min
B.7 h 45 min
C.6 h 45 min
D.5 h 30 min
Answer: A.8 h 45 min
Explanation: 1.Walking to to a viewpoint+Driving back=6 hours 45 minutes
2.Driving to a viewpoint+Driving back=6 hours 45 minutes - 2 hours=4 hours 45 minutes, thereforeone way driving=4 hours 45 minutes/2 =2 hours 22.5 minutes.
3. From 1.one way driving=6 hours 45 minutes-2 hours 22.5 minutes=4 hours 22.5 minutes.
4.Walking to to a viewpoint+Walking back Q=4 hours 22.5 minutes+4 hours 22.5 minutes=8 hours 45 minutes.
Answer: A.
Question: I. a2 + 11a + 30 = 0,
II. b2 + 6b + 5 = 0 to solve both the equations to find the values of a and b?
A.If a < b
B.If a ≤ b
C.If the relationship between a and b cannot be established
D.If a > b
Answer: B.If a ≤ b
Explanation: I. (a + 6)(a + 5) = 0
=> a = -6, -5
II. (b + 5)(b + 1) = 0
=> b = -5, -1 => a ≤ b
ANSWER:B
Question: A man swims downstream 30 km and upstream 18 km taking 3 hours each time, what is the speed of the man in still water?
A.2
B.8
C.9
D.1
Answer: B.8
Explanation: 30 --- 3 DS = 10
? ---- 1
18 ---- 3 US = 6
? ---- 1 M = ?
M = (10 + 6)/2 = 8
Answer:B
Question: What is the highest integer that is the sum of 2 distinct prime integers, each lesser than 60 ?
A.107
B.112
C.113
D.129
Answer: B.112
Explanation: A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. Here are the first few prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, etc.
Immediate two prime numbers before 60 are - 59 and 53
Sum = 59 + 53 = 112
Answer - B
Question: The only items of clothing at Michelle’s Boutique are 4 shirts, 8 pairs of pants and 18 ties. What is the probability of randomly selecting 2 ties out of all the items in Michelle’s Boutique?
A.51/145
B.9/25
C.3/5
D.94/145
Answer: A.51/145
Explanation: We have 4 shirts, 8 pairs of pants and 18 ties. i.e 30 items
Total ways of picking two items out of all = 30C2 = 435
Total ways of picking two items out of all TIES = 18C2 = 153
Required Probability = 153/435 = 51/145
Answer: Option A
Question: If 20 liters of chemical X are added to 80 liters of a mixture that is 15% chemical X and 85% chemical Y, then what percentage of the resulting mixture is chemical X?
A.30%
B.32%
C.35%
D.38%
Answer: B.32%
Explanation: The amount of chemical X in the solution is 20 +0.15(80) = 32 liters.
32 liters / 100 liters = 32%
The answer is B.
Question: If d is the standard deviation a, b, and c, what is the standard deviation of a +2, b + 2, c + 2 ?
A.2d
B.d
C.2d+2
D.8d
Answer: B.d
Explanation: CONCEPT: Standard Deviation is Defined as Average Deviation of Terms in the set from the Mean value of the set. i.e.
1) It depends on the separation between the successive terms of the set
2) If a Constant Value is Added/Subtracted in every terms of set then the Separation between successive terms does NOT change Hence S.D. remains Constant
e.g.{1, 2, 3, 4, 5} will have same standard Deviation as {1+10, 2+10, 3+10, 4+10, 5+10}
3) If a Constant Value is Multiplied in every terms then the Separation between succesive terms gets multiplied by the constant Hence S.D. remains gets multiplied by same Number
e.g. {0.7, 1.4, 2.1, 2.8, 3.5} will have Standard Deviation = 0.7* Standard deviation of set {1, 2, 3, 4, 5}
When 2 is added in each term of set {a, b,c} then the new set {a+2, b+2, c+2} will remain same as the previous standard deviation i.e. d
Answer: B
Question: Of the 150 employees at company X, 80 are full-time, and 100 have worked at company X for at least a year. There are 10 employees at company X who aren’t full-time and haven’t worked at company X for at least a year. How many full-time employees of company X have worked at the company for at least a year?
A.10
B.30
C.50
D.80
Answer: A.10
Explanation: Full time employee who have NOT worked for at least one year = a
Full time employee who have worked for at least one year = b
NON Full time employee who have worked for at least one year = c
NON Full time employee who have NOT worked for at least one year = d
a+b+c+d = 150
a+b = 80
i.e. c+d = 70
b+c = 100
i.e. a+d = 50
d = 20
i.e. c = 70-20 = 50
i.e. b = 100-50 = 50
i.e. a = 80-50 = 30
b = 10
Answer: Option A
Question: Simplify
16âˆ’[2âˆ’(6+2(7âˆ’8âˆ’5Â¯Â¯Â¯Â¯Â¯Â¯Â¯Â¯Â¯Â¯Â¯))]
A.23
B.25
C.28
D.30
Answer: C.28
Explanation: Explanation:
=16âˆ’[2âˆ’(6+2(7âˆ’8+5))]
(Please check due to overline, sign has been changed)
=16âˆ’[2âˆ’(6+2Ã—4))]
=16âˆ’[âˆ’12]=16+12=28
Option C
Question: Three investors, A, B, and C, divide the profits from a business enterprise in the ratio of 5 : 7 : 8, respectively. If investor A earned $ 2,000, how much money did investors B and C earn in total?
A.$4,000
B.$6,000
C.$5,600
D.$9,500
Answer: B.$6,000
Explanation: Let profit for A = 5x
profit for B = 7x
profit for C = 8x
Investor A earned = 2000
5x = 2000=>x=400
Total profit for B and C = 7x+ 8x = 15x
Therefore , 15x = 15*400= 6,000
Answer B
Question: Sandy walks around a circular field at the rate of one round per hour while Molly runs around it at the rate of seven rounds per hour. If they start in the same direction from the same point, how many minutes will it take until they meet again?
A.5
B.8
C.10
D.12
Answer: C.10
Explanation: Since Sandy and Molly move in the same direction along the circle, they will first meet each other when there is a difference of one round between the two.
The relative speed of Sandy and Molly is 7 - 1 = 6 rounds per hour.
The time required to complete one round at this speed is 1/6 hours = 10 minutes.
The answer is C.
Question: In each term of a sequence, 5 is added to get the next term. If the first term is 3, what is the seventy-first term?
A. 332
B. 353
C. 312
D. 360
Answer: B. 353
Explanation: 1rst term + 70 terms = 3 + 5+5+5+5+5+5+5+...+5 (70 times)
3 + (5 x 70) = 3 + 350 = 353
Answer B
Question: If the positive integer x leaves a remainder of 2 when divided by 8, what will the remainder be when x + 9 is?
A.0
B.1
C.2
D.3
Answer: D.3
Explanation: x = 8q +2
x +9 =8q+2+9
8q+11 this can be furthur written as 8q +8 +3 = 8(q+1)+3
Remainder 3. Ans D.
Question: 8 x 2.25- 5 x 0.85/2.5= ?
A.3.8
B.10
C.5
D.5.5
Answer: D.5.5
Explanation: Given Expression
= (18-4.25/2.5
= 13.75/2.5= 137.5/25
= 5.5
Answer is D.
Question: Worker A takes 8 hours to do a job. Worker B takes 10 hours to do the same Job.How long should it take both A and B, working together but independently, to do the same job?
A.70 hours
B.40/9 hours
C.9 hours
D.16 hours
Answer: B.40/9 hours
Explanation: A’s 1 hour's work = 1/8
B's 1 hour's work = 1/10
(A + B)'s 1 hour's work = (1/8) +(1/10)=9/40
Both A and B will finish the work in 40/9 days.
Option B is answer
Question: David bought 4 pens with the average cost of $2. If David also buys the fifth pen with the price of $ 3, what is the average (arithmetic mean) price of those 5 pens?
A.$2.2
B.$2
C.$3.2
D.$4
Answer: B.$2
Explanation: 4 pens -> Total cost = 4 * Avg cost = 4*2 = 8
Fifth pen cost = 3
Total cost for 5 pens= 8+3 = 11
AM = 11/5 = 2.2
Hence B
Question: What is the true discount on a bill of Rs.2916 due in 3 years hence at 8% C.I.?
A.rs.600
B.rs.601
C.rs.602
D.rs.603
Answer: C.rs.602
Explanation: Explanation:
PW = Amount/(1+R100)T.
Answer: C
Question: The ratio between the speeds of two trains is 7: 8. If the second train runs 440 kms in 4 hours, then the speed of the first train is:
A.47.4 km/hr
B.57.19 km/hr
C.68.13 km/hr
D.96.25 km/hr
Answer: D.96.25 km/hr
Explanation: Let the speed of two trains be 7x and 8x km/hr.
Then, 8x = (440/4) = 110
x = (110/8) = 13.75
Hence, speed of first train = (7 x 13.75) km/hr = 96.25 km/hr.
Answer : D
Question: If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 2 strokes ?
A.3/4
B.7/8
C.1/4
D.1/8
Answer: A.3/4
Explanation: Left After 1st stroke = 1/2
Left After 2nd stroke = 1/2 * 1/2 = 1/4
So removed = 1- 1/4 = 3/4
Question: A and B rent a pasture for 10 months. A put in 80 cows for 7 months. How many can B put in for the remaining 3 months, if he pays half as much again as A?
A.126
B.278
C.281
D.280
Answer: D.280
Explanation: 80* 7: x* 3 = 1:1 1/2
560: 3x = 2: 3
x = 280
Answer: D
Question: The speed of the boat in still water is 12km/hr. and the speed of the stream is 3km/hr. Find the distance travelled downstream in 12 minutes.
A.160 km
B.180 km
C.190 km
D.170 km
Answer: B.180 km
Explanation: speed of the boat in downstream =speed of the water + speed of the boat
=12+3 =15km/hr Distance travelled in 12 minutes =15 *12 = 180km. Answer : B
Question: What will be the cost of building a fence around a square plot with area equal to 64 sq ft, if the price per foot of building the fence is Rs. 58?
A.3944
B.2882
C.2999
D.1856
Answer: D.1856
Explanation: Let the side of the square plot be a ft.
a2 = 64 => a = 8
Length of the fence = Perimeter of the plot = 4a = 32 ft.
Cost of building the fence = 32 * 58 = Rs. 1856.
Answer: D
Question: John is filling out the office space for his employees. There are 8 people in his office, and he must assign 8 employees to the following positions: 2 next to his cabin, 2 near the gate, 2 in center, and 2 near coffee machine. Only 2 employees are secretary and can sit next to his cabin, and they cannot sit anywhere else. The other employees can sit anywhere they like. How many different groupings are possible?
A.100
B.90
C.80
D.70
Answer: B.90
Explanation: Secretary can sit in 2C2 ways = 1
Near the gate we can have 6C2 combinations (2 secretaries are already having a place)
In the center we can have 4 C2 employees as 4 already have a place
Near coffee machine we can have 2C2 employees as all other place are taken
Number of selection = 2C2 * 6C2 * 4C2 * 2C2 = 90
Ans: B
Question: The age of Amit is 3 times that of his son. 15 years ago, Amit was 9 times as old as his son, What will be the age of Amit after 15 years?
A.35 years
B.60 years
C.75 years
D.65 years
Answer: C.75 years
Explanation: Let the present age of Amit and his son be x and y respectively.
Then, x = 3y ...(i)
(x -15) = 9(y - 15)
or x - 15 = 9y -135 .
x - 9y = - 120 ...(ii)
Solving (i) and (ii),
we get y = 20 and x = 60
Thus Age of Amit after 15 years = 60 + 15 = 75 years
ANSWER:C
Question: The second day of a month is Friday, What will be the last day of the next month which has 31 days?
A.Friday
B.Saturday
C.Wednesday
D.Data inadequate
Answer: D.Data inadequate
Explanation: Explanation :
We cannot find out the answer because the number of days of the current month is not given. Answer : Option D
Question: Find the odd man out. 0,3,7,15,24
A.8
B.10
C.9
D.6
Answer: A.8
Explanation: 1^2-1=0
2^2-1=3
3^2-1=8
4^2-1=15
5^2-1=24
Hence, it is clear that 8 should have come instead of 7
Answer : Option A
Question: A regular hexagon is inscribed in a circle. If A and B are adjacent vertices of the pentagon and O is the center of the circle, what is the value of ∠OAB ?
A.48 degrees
B.60 degrees
C.72 degrees
D.84 degrees
Answer: B.60 degrees
Explanation: its a regular hexagon so divide the globe by 6.
= 360/6
= 60
72 would be the angle at O.
Angles at A and B are equivalent, so
60 + 2x = 180
2x = 120
x = 60
Angles OAB and OBA will be 60 degrees each.
B
Question: A box measuring 49 inches long by 21 inches wide by 14 inches deep is to be filled entirely with identical cubes. No space is to be left unfilled. What is the smallest number of cubes that can accomplish this objective?
A.17
B.42
C.54
D.108
Answer: B.42
Explanation: least number of cubes will be required when the cubes that could fit in are biggest.
7 is the biggest number that could divide all three, 49, 21 and 14.
Thus side of cube must be 7, and total number of cubes = 49/7 * 21/7*14/7 = 42
Ans B it is.
Question: If 20% of a = b, then b% of 20 is the same as :
A.4% of a
B.6% of a
C.8% of a
D.10% of a
Answer: A.4% of a
Explanation: 20% of a = b -> 20/100 a = b
b% of 20 = b/100*20 = 4% of a
ANSWER A
Question: Narendra started a business, investing 30000. Six months later, Chandan joined him with 15000. If they make a profit of 15000 at the end of the year, what should be the share of Narendra?
A.A)Rs.7000
B.B)Rs.12000
C.C)Rs.8500
D.D)Rs.8600
Answer: B.B)Rs.12000
Explanation: The ratio of their investments = 30000 × 12 : 15000 × 6 = 4 : 1.
:. Narendra’s share on profit of Rs.15000 = 15000 × 4/5 = Rs.12000.
B)
Question: In what ratio must a grocer mix two varieties of pulses costing Rs. 15 and Rs. 20 per kg respectively so as to get a mixture worth Rs. 16.50 kg?
A.3 : 7
B.5 : 7
C.7 : 3
D.7 : 5
Answer: C.7 : 3
Explanation: By the rule of alligation:
Cost of 1 kg pulses of 1st kind Rs. 15
Cost of 1 kg pulses of 2nd kind Rs. 20
Mean Price Rs. 16.50
Required rate = 3.50 : 1.50 = 7 : 3.
Answer:C
Question: One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill tank in 40 min, then the slower pipe alone will be able to fill the tank in?
A.160
B.787
C.144
D.128
Answer: A.160
Explanation: Let the slower pipe alone fill the tank in x min.
Then, faster pipe will fill it in x/3 min.
1/x + 3/x = 1/40
4/x = 1/40 => x = 160 min.
Answer: A
Question: The fourth proportional to 6, 14 and 18 is?
A.21
B.42
C.77
D.88
Answer: B.42
Explanation: (14*18)/6 = 42
Answer: B
Question: A certain car dealership sells economy cars, luxury cars, and sport utility vehicles. The ratio of economy to luxury cars is 3:2. The ratio of economy cars to sport utility vehicles is 4:2. What is the ratio of luxury cars to sport utility vehicles?
A.9:8
B.8:9
C.3:2
D.8:6
Answer: D.8:6
Explanation: The ratio of economy to luxury cars is 3:2 --> E:L = 3:2 = 12:8.
The ratio of economy cars to sport utility vehicles is 4:2 --> E:S = 4:2 = 12:6.
Thus, L:S = 8:6.
Answer: D.
Question: It takes 1.5 hours for Tim to mow the lawn. Linda can mow the same lawn in 2 hours. How long will it take John and Linda, work together, to mow the lawn?
A.51.1 minutes
B.51.3 minutes
C.51.5 minutes
D.51.7 minutes
Answer: C.51.5 minutes
Explanation: We first calculate the rate of work of John and Linda
John: 1 / 1.5 and Linda 1 / 2
Let t be the time for John and Linda to mow the Lawn. The work done by John alone is given by
t * (1 / 1.5)
The work done by Linda alone is given by
t * (1 / 2)
When the two work together, their work will be added. Hence
t * (1 / 1.5) + t * (1 / 2) = 1
Multiply all terms by 6
6 (t * (1 / 1.5) + t * (1 / 2) ) = 6
and simplify
4 t + 3 t = 6
Solve for t
t = 6 / 7 hours = 51.5 minutes.
Answer C
Question: Annie has 100 cards numbered 1 through 100. If she deals five cards to Alex, without replacing any of them, what is the probability that Alex will get five consecutive numbers?
A.95!/100!
B.96!/100!
C.(95! X 5!)/100!
D.(96! X 5!)/100!
Answer: D.(96! X 5!)/100!
Explanation: Alex to get 5 consecutive cards in ascending order, to have 5 consecutive at the end is good enough.
There are 96 consecutive numbers in 100: {1, 2, 3, 4, 5}, {2, 3, 4, 5, 6}, ..., {96, 97, 98, 99, 100};
Total ways to pick 5 cards out of 100 is C5100C1005;
So, P=\frac{favorable \ outcomes}{total \ # \ of \ outcomes}=\frac{96}{C^5_{100}}=\frac{5!*96!}{100!}.
Answer: D.
Question: If a and b are even numbers, which of the following CANNOT be the value of a-b?
A.10
B.14
C.21
D.24
Answer: C.21
Explanation: 21 is an odd number and the subtraction of two even number should be an even number..
ans C
Question: If there is an equal probability of a child being born a boy or a girl, what is the probability that a couple who have 3 children have two children of the same sex and one of the opposite sex?
A.1/3
B.2/3
C.1/4
D.3/4
Answer: D.3/4
Explanation: Let boy be represented by B and girl by G.
The possible outcomes of two children of same sex and one of opposite sex can be:
BBG OR GBB OR BGB OR GGB OR BGG OR GBG
(1/2*1/2*1/2) + (1/2*1/2*1/2) + (1/2*1/2*1/2) + (1/2*1/2*1/2) + (1/2*1/2*1/2) + (1/2*1/2*1/2)
1/8 + 1/8 + 1/8 + 1/8 + 1/8 + 1/8 = 6/8 = 3/4
ANSWER:(D)
Question: The average temperature of the town in the first four days of a month was 58 degrees. The average for the second, third, fourth and fifth days was 62 degrees. If the temperatures of the first and fifth days were in the ratio 7 : 8, then what is the temperature on the fifth day ?
A.62 degrees
B.64 degrees
C.128 degrees
D.66 degrees
Answer: C.128 degrees
Explanation: Explanation:
Sum of temperatures on 1st, 2nd, 3rd and 4th days = (58 * 4) = 232 degrees ... (1)
Sum of temperatures on 2nd, 3rd, 4th and 5th days - (62 * 4) = 248 degrees ....(2)
Subtracting (1) From (2), we get :
Temp, on 5th day - Temp on 1st day = 16 degrees.
Let the temperatures on 1st and 5th days be 7x and 8x degrees respectively.
Then, 8x - 7x = 16 or x = 16. Answer: C
Temperature on the 5th day = 8x = 128 degrees.
Question: The mean of 30 values was 250. It was detected on rechecking that one value 165 was wrongly copied as 135 for the computation of the mean. Find the correct mean.
A.151
B.149
C.152
D.251
Answer: D.251
Explanation: Corrected mean = 250×30−135+165/30
= 7500−135+165/30
=7530/30=251
Answer D
Question: 105*2
A.11025
B.23889
C.29088
D.1999
Answer: A.11025
Explanation: Here d = 5.
100 + 2 ×× 5 / 25 = 11025
Answer:A
Question: A certain fruit stand sold orange for $0.70 each and bananas for $0.50 each. If a customer purchased both apples and bananas from the stand for a total of $6.30, what total number of apples and bananas did the customer purchase ?
A.12
B.13
C.14
D.11
Answer: D.11
Explanation: Some multiple of 7 + Some multiple of 5 should yield 63. To get to a some multiple of 5, we should ensure that a 3 or 8 (5+3) should be a multiple of 7.
63 is a direct multiple of 7, however in this case there won't be any bananas. Hence the next option is to look for a multiple of 7 that has 8 as the unit digit. 28 satisfies this hence no. of apples is 4 and no of bananas is 7
D
Question: A clock strikes every hour once at 1.00 twice at 2.00 and so on. the clock takes 6 seconds to strike 5.00 and 12 seconds to strike 9.00 the time needed to strike 1.00 is negligible. how long does the clock need for all its striking in 24 hours?
A.138
B.198
C.267
D.297
Answer: B.198
Explanation: The clock takes 12 secs to strike 9.00. So there are 8 gaps between 9 strikings. So the gap between the striking is 12/8 = 1.5 seconds.
To strike 2.00 it takes = 1.5 seconds.
To strike 3.00 it takes = 3 seconds.
To strike 4.00 it takes = 4.5 seconds
................
................
To strike 12.00 it takes = 16.5 seconds.
So it takes a total of 1.5 + 3 + 4.5 + . . . . . . + 16.5 = 1.5 ( 1 + 2 + 3 + .... + 11) = 99 seconds to strike 12 hours.
For 24 hours it takes 99 × 2 = 198 seconds.
Answer:B
Question: The average runs of a cricket player of 10 innings was 32. How many runs must he makes ih his next innings so as to increase his average of runs by 4?
A.2
B.4
C.70
D.76
Answer: D.76
Explanation: Sol.
Average after 11 innings = 36.
Therefore required numbert of runs
= (36 × 11) – (32 × 10)
= 396 - 320
= 76.
Answer D
Question: if 85% of the population of an ant colony is red, and of these 45% are females, then what % of the total ant population are male red ants?
A.46.75
B.40
C.33.66
D.66.66
Answer: A.46.75
Explanation: 55% are males
percentage of male red ants is 55*.85=46.75
ANSWER:A
Question: workers decided to raise Rs.3 lacs by equal contribution from each. Had they contributed Rs.50 eachextra, the contribution would have been Rs.3.25 lacs . How many workers were they?
A.200
B.250
C.500
D.550
Answer: C.500
Explanation: N * 50 = (325000 - 300000) = 25000
N = 25000 / 50
= 500
C
Question: The smallest value of n, for which 2n+1 is not a prime number, is
A.3
B.4
C.5
D.6
Answer: B.4
Explanation: (2×1 + 1) = 3.
(2×2 + 1) = 5.
(2×3 + 1) = 7.
(2×4 + 1) = 9.
which is not prime , n=4.
ANSWER:B
Question: Y and Z started a business investing Rs. 70,000 and Rs. 30,000 respectively. In what ratio the profit earned after 5 years be divided between Y and Z respectively?
A.6:3
B.3:7
C.7:3
D.3:6
Answer: C.7:3
Explanation: Y:Z = 70000 : 30000 = 7:3.
ANSWER:C
Question: Ravi purchased 20 dozens of toys at the rate of Rs. 350 per dozen. He sold each one of them at the rate of Rs. 33. What was his percentage profit?
A.23%
B.1.2%
C.13.14%
D.34.1%
Answer: C.13.14%
Explanation: C
C.P. of 1 toy = 350/12 = Rs. 29.16
S.P of 1 toy = Rs. 33
Profit = 3.83/31.25 * 100 = 13.14%
Question: For all numbers a and b, the operation is defined by ab = (a + 2)(b – 3).
If 3y = –50, then y =
A. –15
B. –7
C. 3
D. 6
Answer: B. –7
Explanation: (3+2)(y-3)=-50..
y-3=-10..
y=-7
B
Question: Sum Sam and Product Pete are in class when their teacher gives Sam the Sum of two numbers and Pete the product of the same two numbers (these numbers are greater than or equal to 2). They must figure out the two numbers.
Sam: I don't know what the numbers are Pete.
Pete: I knew you didn't know the numbers... But neither do I.
Sam: In that case, I do know the numbers.1
What are the numbers?
A.1-2
B.1-3
C.2-4
D.3-4
Answer: D.3-4
Explanation: Since Sam knows the sum of the numbers (x + y) he would only know the answer immediately if the sum was 4 (2 + 2) or 5 (3 + 2). Then when Pete (who knows x*y) knew that Sam didn't know the answer the product must have several numbers that add up to the sum (7 = 3 + 4, 7 = 5 + 2). When Pete doesn't know the answer at this point we know the product must have more than one pair of viable factors (12 = 3 * 4, 12 = 6 * 2). At this point Sam knows the numbers are 3 and 4 because they are the only numbers that meet these criteria.
Question: The value of a scooter depreciates in such a way that its value of the end of each year is 3/4 of its value of the beginning of the same year. If the initial value of the scooter is Rs.40,000, what is the value at the end of 6 years ?
A.3277
B.2977
C.7119
D.6077
Answer: C.7119
Explanation: Explanation: 40,000*(3/4)^6
Answer:C
Question: At the end of three years what will be the compound interest at the rate of 10% p.a. on an amount of Rs.15000?
A.4965
B.1879
C.2779
D.2672
Answer: A.4965
Explanation: A = 15000(11/10)^3
= 19965
= 15000
----------
4965
Answer: A