RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: An engineer undertakes a project to build a road 10 km long in 60 days and employs 30 men for the purpose. After 20 days, he finds only 2 km of the road has been completed. Find the (approximate) number of extra men he must employ to finish the work in time.
A.20
B.15
C.30
D.45
Answer: C.30
Explanation: 30 workers working already
Let x be the total men required to finish the task in next 40 days
2 km done hence remaining is 8 km
Also, work has to be completed in next 40 days (60 - 20 = 40)
We know that, proportion of men to distance is direct proportion
and, proportion of men to days is inverse proportion
Hence, X = (30 * 8 * 20) / (2 *40)
thus, X = 60
Thus, more men needed to finish the task = 60-30=30
Answer : C
Question: If A and B get profits of Rs. 6000 and Rs. 4000 respectively at the end of year the ratio of their investments are ?
A.1:4
B.3:2
C.2:3
D.2:5
Answer: B.3:2
Explanation: profit=Investment * Time
so,
6000=i1 *1=6000
4000=i2 * 1= 4000
i1/i2=6000/4000=3/2
ANSWER:B
Question: Mr. Karan borrowed a certain amount at 6% per annum simple interest for 9 years. After 9 years, he returned Rs. 8110/-. Find out the amount that he borrowed.
A.Rs. 4,900
B.Rs. 5,000
C.Rs. 5,100
D.Rs. 5266
Answer: D.Rs. 5266
Explanation: Explanation:
Let us assume Mr. Karan borrowed amount is Rs. A. (the principal)
By formula of simple interest, S.I. = PRT / 100
Where P = The principal, R = Rate of interest as a %, T = Time in years
S.I. = (P * 6 * 9)/100 = 54 P/100
Amount = Principal + S.I.
8110 = P + (54P/100)
8110 = (100P + 54P)/100
8110 = 154P/100
P = (8110 * 100)/154 = Rs. 5266.233
ANSWER D
Question: Of the 120 passengers on Flight 750, 40% are female. 10% of the passengers sit in first class, and the rest of the passengers sit in coach class. If 1/3 of the passengers in first class are male, how many females are there in coach class?
A.40
B.48
C.50
D.52
Answer: A.40
Explanation: Number of passengers on flight = 120
Number of female passengers= .4*120 = 48
Number of passengers in first class = (10/100)* 120 = 12
Number of passengers in coach class = (90/100)* 120 = 108
Number of male passengers in first class = 1/3 * 12 = 4
Number of female passengers in first class = 12-4 = 8
Number of female passengers in coach class = 48 - 8 = 40
Answer A
Question: How much 70% of 100 is greater than 60% of 80?
A.18
B.99
C.22
D.26
Answer: C.22
Explanation: (70/100) * 100 – (60/100) * 80
70- 48 = 22
Answer: C
Question: In a group of 80 children and 10 youngsters, each child got sweets that are 15% of the total number of children and each youngster got sweets that are 25% of the total number of children. How many sweets were there?
A.1160
B.1169
C.1162
D.1122
Answer: A.1160
Explanation: Number of sweets each child got = 15% of 80 = 15/100 * 80 = 12.
Number of sweets 80 children got = 80 * 12 = 960.
Number of sweets each youngster got = 25% of 80 = 25/100 * 80 = 20.
Number of sweets 10 youngsters got = 10 * 20 = 200.
Total number of sweets = 960 + 200 = 1160.
Answer:A
Question: Patrick purchased 80 pencils and sold them at a loss equal to the selling price of 30 pencils. The cost of 80 pencils is how many times the selling price of 80 pencils?
A. 0.75
B. 0.8
C. 1.375
D. 1.4
Answer: C. 1.375
Explanation: Say the cost price of 80 pencils was $80 ($1 per pencil) and the selling price of 1 pencil was p.
Selling at a loss: 80 - 80p = 30p --> p = 8/11.
(cost price)/(selling price) = 1/(8/11) = 11/8 = 1.375.
Answer: C.
Question: For each positive integer,the quantitySn is defined such thatSn+3=(Sn)^2 -S(n+1).in addition ,S2=1.then which of the following must be true.
A.a)S4 +S3 +1=0
B.b)(S1)^2 +S4 +2=0
C.c) ifS1=-1thenS4 is also equal to-1.
D.d) ifS4 =-7thenS1=-2.
Answer: B.b)(S1)^2 +S4 +2=0
Explanation: Since all the answers include S4, let's start from there.
S4=S2^2-S3
S3=S1^2-S2
Substituting S3 into the first equation we get:
S4=S2^2-(S1^2-S2)
Since S2=1
S4=1-(S1^2-1)
S4=2-S1^2
We need S1^2 in order to calculate S4.
E) provides S1 and from there we can calculate S4:
S4=2-(-3)^2
S4=-7
Correct.
As a side note, I would be very careful with answers in the formif S4=x then S1=y(such as option D ), as we are dealing with S1^2 (not S1), S1 can have two different values and it can not be determined for sure which root is the right answer.
For example:
If S4=-7 then S1=3 :
if we substitute S4 with - 7 we get:
-7=2-S1^2
S1^2=9
now S1 can be +/-3 !!
B
Question: If b is an even integer and b/18 is an odd integer, which of the following is NOT an even integer?
A.(b^2)/54
B.(b^2)/8
C.(b^2)/9
D.(b^2)/6
Answer: B.(b^2)/8
Explanation: since b is an even integer and b/18 is an odd integer. thus maximum power of 2 in a is one. why ?? because if the power of 2 in the expression has been 2 or greater, then the b/18 must have been an even integer. (18=2*3^2. as 18 contain only one 2 in the expression)
now, any expression in which we have 4 at the denominator will be odd. out of the given options only 8 is a multiple of 4. hence answer should be B
Question: If n is a positive integer, which one of the following numbers must have a remainder of 2 when
divided by any of the numbers 4, 5, and 6?
A.125n + 2
B.240n + 2
C.280n + 2
D.390n + 2
Answer: B.240n + 2
Explanation: The numbers 4, 5, and 6 all divide 240 so they all divide 240n.
When we divide (240n + 2) by 4, 5, or 6, the remainder must be 2.
The answer is B.
Question: Set R consists of all even integers between 2 and 100, inclusive. Set X is derived by reducing each term in set R by 50, set Y is derived by multiplying each term in set R by 1.5, and set Z is derived by dividing each term in set R by -4. Which of the following represents the ranking of the three sets in descending order of standard deviation?
A. X, Y, Z
B. X, Z, Y
C. Y, Z, X
D. Y, X, Z
Answer: D. Y, X, Z
Explanation: Set R - {2, 4, ..., 100};
Set X - {-48, -46, ..., 50};
Set Y - {3, 6, ..., 150};
Set Z - {-2/4, -4/4, ..., -100/4} = {-1/2, -1, -3/2, ..., -25}.
If we add or subtract a constant to each term in a set the SD will not change, so sets R and X will have the same SD.
If we increase or decrease each term in a set by the same percent (multiply by a constant) the SD will increase or decrease by the same percent, so set Y will have 1.5 times greater SD than set R and set Z will have 4 times less SD than set R (note SD can not be negative so SD of Z wil be SD of R divided by 4 not by -4).
So, the ranking of SD's in descending order is: Y, R=X, Z.
Answer: D.
Question: Two numbers are in the ratio of 5:7. If 25 be subtracted from each, they are in the ratio of 35:59. Find the numbers?
A.60,88
B.60,81
C.68,88
D.60,84
Answer: D.60,84
Explanation: (5x-25):(7x-25)
= 35:59
x = 12 => 60,84
Answer: D
Question: In a certain city each of 6 Bus lines is represented by a colored flag. Each flag consists of either a single color or a pair of two different colors. If each bus lines has a different flag, what is the minimum number of colors needed for the flags. (Assume that the order of colors in a pair on a flag does not matter.)
A.2
B.4
C.3
D.1
Answer: C.3
Explanation: C.3:
if we have 3 colors we can choose pairs in 3C2 ways = 3 and single color flags are 3. Therefore total number of flags = 6.
ANS C.
Question: Sum of the squares of 3 no.'s is 62 and the sum of their products taken two at a time is 131. Find the sum?
A.20
B.24
C.26
D.18
Answer: D.18
Explanation: (a + b + c)2 = a2 + b2 + c2 + 2(ab +bc + ca) = 62 + 2* 131
a + b + c = √324 = 18
D
Question: The average of three consecutive odd numbers is 12 more than one third of the first of these numbers. What is the last of the three numbers?
A.15
B.17
C.19
D.21
Answer: C.19
Explanation: x,x+2,x+4 are three odd numbers
(x+x+2+x+4)/3=12+(x/3)
x=15
last no.=x+4=19
ANSWER:C
Question: A 9 meter long wire is cut into two pieces. If the longer piece is then used to form a perimeter of a square, what is the probability that the area of the square will be more than 4 if the original wire was cut at an arbitrary point?
A.1/6
B.1/5
C.2/9
D.1/3
Answer: C.2/9
Explanation: A square with an area of 4 has a perimeter of 8.
For the area to be >4, the longer piece must be >8.
The wire must be cut within 1 meters from either end.
The probability of this is 2/9.
The answer is C.
Question: The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present. If the concentration of chemical B is increased by 80%, which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?
A.100% decrease
B.50% decrease
C.40% decrease
D.45% increase
Answer: D.45% increase
Explanation: The rate of reaction is invesrsly proportional to the concentration of chemical B present. It used to have B=1 . Now that B is increased by 80%. So the new equation would be 2B=(1/2). In order for the rate of reaction to still be 1, we need to change the concentration of A to yield a 2. It used to be A^2=1, now the new equation should be (sqrt(2)*A)^2=2. The change in the concentration of A can be calculated as (sqrt(2) -1)/1 or approximately 40% increase. Answer D.
Question: A man sells a horse for Rs.800 and loses something, if he had sold it for Rs.980, his gain would have been double the former loss. Find the cost price of the horse?
A.860
B.900
C.875
D.950
Answer: A.860
Explanation: CP = SP + 1CP = SP - g
800 + x = 980 - 2x
3x = 180 => x = 60
CP = 800 + 60 = 860
ANSWER A
Question: The ages of two persons differ by 12 years. If 5 years ago, the elder one be 5 times as old as the younger one, their present ages (in years) are respectively
A.20,20
B.20,8
C.25,15
D.30,10
Answer: B.20,8
Explanation: Explanation:
Let their ages be x and (x + 12) years.
5 (x - 5) = (x + 12 - 5) or 4x = 32 or x = 8.
Their present ages are 20 years and 8 years
Option B
Question: The area of a triangle is with base 10m and height 10m?
A.11
B.10
C.50
D.122
Answer: C.50
Explanation: 1/2 * 10 *10= 50 m2
Answer: C
Question: 8 men can do a piece of work in 12 days. 4 women can do it in 48 days and 10 children can do it in 24 days. In how many days can 18 men, 4 women and 10 children together complete the piece of work?
A.5 days
B.15 days
C.28 days
D.4 days
Answer: D.4 days
Explanation: Explanation:
1 man’s 1 day’s work = 1/8 × 12 = 1/96
18 men’s 1 day’s work = 1 × 18/96 = 3/16
1 woman’s 1 day’s work = 1/192
4 women’s 1 day’s work = 1/192 × 4 = 1/48
1 child’s 1 day’s work = 1/240
10 children’s 1 day’s work = 1/24
Therefore, (18 men + 4 women + 10 children)’s 1 day’s work = 3/16 + 1/48 + 1/24
= 1/4
The required No. of days = 4 days
Answer: Option D
Question: The cost of a one-family home was $ 120,000 in 1980. In 1988, the price had increased to $ 198,000. What was the percent increase in the cost of the home?
A.65%
B.50%
C.55%
D.40%
Answer: A.65%
Explanation: Increase = 198000-120000 = 78000
% increase = 78000*100/120000 = 65%
Answer: option A
Question: A person takes 5hrs 45 min in walking to a place and riding back. He would have gained 5 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.10 hours 45 min
Answer: D.10 hours 45 min
Explanation: ----------------------------------------------------------------
Solution 1
----------------------------------------------------------------
Given that time taken for riding both ways will be 5 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 - 5 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 +5 hours = 10 hours 45 min
D
Question: Xavier starts from P towards Q at a speed of 50 kmph and after every 12 mins increases his speed by 10 kmph. If the distance between P and Q is 52km, then how much time does he take to cover the distance?
A.40
B.60
C.48
D.70
Answer: C.48
Explanation: first 12min = 50 *12/60 =10 km
2nd 12min = 60*12/60 = 12km
3rd 12 min = 70*12/60 = 14 km
4th 12 min = 80 *12/60 = 16 KM
TOTAL time 12.4 =48 min
C
Question: What is the sum of all the even numbers between 31 and 99, inclusive?
A.3,000
B.2,562
C.2,500
D.2,180
Answer: D.2,180
Explanation: To figure this problem out, you just have to add all the even numbers, starting with 32.
32+34+36+38 and so on, all the way up to 98. You'll get 2,180, so
Final Answer:
D
Question: The daily high temperatures were recorded at an Antarctic weather station. If a temperature of -38.2 degrees Celsius is 2 units of standard deviation below the mean temperature, and a temperature of -22.6 degrees Celsius is 4 units of standard deviation above the mean, which of the following temperatures is 2 unit of standard deviation above the mean?
A.-35.6 degrees Celsius
B.-33.0 degrees Celsius
C.-30.4 degrees Celsius
D.-27.8 degrees Celsius
Answer: D.-27.8 degrees Celsius
Explanation: Let us suppose mean = M and SD = d.
So, we are given M - 2d = -38.2
and M + 4d = -22.6
solving both the equations, we will get M = -33 an d = 2.6
So, we need to find out M + 2d = -33 + 2*2.6 = -27.8. Hence, D
Question: In a box of 11 pens, a total of 3 are defective. If a customer buys 2 pens selected at random from the box, what is the probability that neither pen will be defective?
A.28/55
B.19/33
C.7/11
D.4/7
Answer: A.28/55
Explanation: P(neither pen is defective) = 8/11*7/10 = 28/55
The answer is A.
Question: Express a speed of 18 kmph in meters per second?
A.10 mps
B.06mps
C.09 mps
D.05 mps
Answer: D.05 mps
Explanation: D
5 mps
18 * 5/18 = 5 mps
Question: Two friends Simpson & Stewie decide to get together
So they start driving cars towards each other. They plan to meet halfway. Each is riding at 6 Km/hr. They live 36 kms apart. Stewie has a pet "eagle" and it starts flying the instant they start traveling. The eagle flies back and forth at 18 Km/hr between them until the two meet.
How many kms does the eagle travel ?
A.54
B.55
C.86
D.45
Answer: A.54
Explanation: A
54
It takes 3 hours for the Simpson & Stewie to meet.
so the eagle flies for 3 hours at 18 Km/hr = 54 kms
Question: Two trains are running in opposite directions in the same speed. The length of each train is 120 meter. If they cross each other in 36 seconds, the speed of each train (in km/hr) is
A.12
B.36
C.28
D.20
Answer: A.12
Explanation: Explanation:
Distance covered = 120+120 = 240 m
Time = 36 s
Let the speed of each train = v. Then relative speed = v+v = 2v
2v = distance/time = 240/36 = 6.667 m/s
Speed of each train = v = 6.667/2 = 3.33 m/s
= 3.33×36/10 km/hr = 12 km/hr
Answer: Option A
Question: The average age of 8 men increases by 2 years when two women are included in place of two men of ages 20 and 24 years. Find the average age of the women?
A.37
B.26
C.30
D.18
Answer: C.30
Explanation: Explanation:
20 + 24 + 8 * 2 = 60/2 = 30
Answer: C
Question: In a certain company, the ratio of the number of managers to the number of non-managers in any department must always be greater than 7 : 37. In the company, what is the maximum number of non-managers in a department that has 11 managers?
A.56
B.57
C.58
D.59
Answer: C.58
Explanation: 11/7 * 37 = 58.1
The answer is C.
Question: Pane can make a handcrafted drum in 4 weeks. Zane can make a similar handcrafted drum in 6 weeks. If they both work together, how many weeks will it take for them to produce 15 handcrafted drums?
A.30
B.36
C.70
D.80
Answer: B.36
Explanation: Method I: the rates solution
“Pane can make a handcrafted drum in 4 weeks. Zane can make a similar handcrafted drum in 6 weeks.” Pane’s rate is (1 drum)/(4 weeks) = 1/4. Zane’s rate is (1 drum)/(6 weeks) = 1/6. The combined rate of Pane + Zane is
R = 1/4 + 1/6 = 3/12 + 2/12 = 5/12
That’s the combined rate. We need to make 15 drums — we have a rate and we have an amount, so use the “art” equation to solve for time:
T = A/R = 15/(5/12) = 15*(12/5) = (15/5)*12 = 3*12 = 36
BTW, notice in the penultimate step, the universal fraction strategy: cancelbeforeyou multiply (Tip #3:http://magoosh.com/gmat/2012/can-i-use- ... -the-gmat/. Mane and Zane need 36 weeks to make 15 drums.
Answer = B.
Question: Two numbers A and B are such that the sum of 5% of A and 4% of B is two-third of the sum of 6% of A and 8% of B. Find the ratio of A : B.
A.2:1
B.1:2
C.1:1
D.4:3
Answer: D.4:3
Explanation: 5% of A% of B = 2/3 (6% of A + 8% of B)
5A/100 = 4B/100 = 2/3(6A/100 + 8B/100)
=>3A=4B
A/B=4/3
A:B=4:3
ANSWER D
Question: An engineer designed a ball so that when it was dropped, it rose with each bounce exactly one-half as high as it had fallen. The engineer dropped the ball from a 16-meter platform and caught it after it had traveled 32.5 meters. How many times did the ball bounce?
A.2
B.6
C.7
D.8
Answer: A.2
Explanation: Ans: 2
Division of total diatance travelled will be 16+16+0.5
A
Question: A train running at a speed of 36 kmph crosses an electric pole in 12 seconds. In how much time will it cross a 350 m long platform?
A.11
B.77
C.36
D.47
Answer: D.47
Explanation: Let the length of the train be x m.
When a train crosses an electric pole, the distance covered is its own length.
So, x = 12 * 36 * 5 /18 m = 120 m.
Time taken to cross the platform = (120 +350)/ 36 * 5/18 = 47 min.
Answer:D
Question: Among the employees of a certain company, 50 percent of the employees are male and 48 percent are female. In this company 70 percent of the male employees are married and 50 percent of the female employees are married. If one employee in the company is randomly selected, approximately what is the probability that he or she is NOT married?
A. 0.3
B. 0.4
C. 0.5
D. 0.6
Answer: B. 0.4
Explanation: Much faster: draw 4 quadrants
______________Male (50%)_____Female (50%)
Married :__________70%____________50%
Not Married:_______30%____________50%
Therefore: the probability of picking one random person Not Married (he or she) is: 0,50 x 0,30 + 0,50 x 0,50 = 0,15 + 0,25 (approx.)
Solution: approx. 0,4 (answer B)
Question: The sale price of an article including the sales tax is Rs. 616. The rate of sales tax is 10%. If the shopkeeper has made a profit of 12%, then the cost price of the article is:
A.500
B.277
C.266
D.288
Answer: A.500
Explanation: 110% of S.P. = 616
S.P. = (616 * 100)/110 = Rs. 560
C.P = (110 * 560)/112 = Rs. 500.Answer: A
Question: subash can copy 50 pages in 10 hrs.subash and prakash together can copy 300 pages in 40 hours.in how much time prakash can copy 20 pages.
A.8
B.10
C.12
D.14
Answer: A.8
Explanation: subhas 's 1 hr copy page=50/10=5 page
(subhas+prakash)'s 1 hr copy page=300/40=7.5 page
from above prakash's 1 hr copy page= 2.5 page
so time taken in 20 page's copy =(20/2.5)=8 hrs
ANSWER :A
Question: The measurement of a rectangular box with lid is 25cmx24cmx18cm. Find the volume of the largest sphere that can be inscribed in the box (in terms of πcm3). (Hint: The lowest measure of rectangular box represents the diameter of the largest sphere)
A.288
B.2302
C.2304
D.8640
Answer: C.2304
Explanation: d=24, r=12;
Volume of the largest sphere= 4/3πr3
= 4/3 *π*12*12*12= 2304πcm3 ANSWER:C
Question: A basketball team scored x points per game in its first n games of the season, and in all the following games it scored an average (arithmetic mean) of y points per game. What was the average number of points per game in its first n + 6 games?
A.x + 3y/(n + 3)
B.x + y/(n + 3)
C.(x + 3y)/(n + 3)
D.(nx + 3y)/(n + 6)
Answer: D.(nx + 3y)/(n + 6)
Explanation: Total points in first n games = nx
Total marks in next 3 games is 3y
So, Average marks in n + 6 games = (nx+3y)/(n+6)
Hence, correct answer will be (D)
Question: A mother and father have seven children, and the family receives an invitation with four tickets to the circus. If the family decides to randomly select the four members who get to attend the circus, but determine that the chosen group must include at least one of the mother and father, how many different groups are possible to send to the circus?
A.70
B.84
C.91
D.108
Answer: C.91
Explanation: Condition 1: Atleast one of the mother and father along with seven children must be selected
Then either - Mother or father = 2C1 = 2 ways for one ticket and 7C3 = 35 ways for other three tickets. Total ways here is 2*35 = 70
Condition 2: Both M and F selected and this is 1 way...then we'll have only two tickets for 7 children..then we can select 7C2 = 21.
Total 70+21 = 91.
Option C.
Question: In how many ways Chief Minister and Minister be elected from a team of 12 members?
A.128
B.134
C.132
D.167
Answer: C.132
Explanation: To do this, if captain is elected first, then we have 12 ways of doing this.
For election of vice-captain, we have only 11 ways left, coz 1 way is already consumed. (Situations like this is called dependent situation. One selection depends upon other selection.)
So, the ans is 12*11 = 132 ways.
C
Question: What is the rate percent when the simple interest on Rs.800 amount to Rs.160 in 4 Years?
A.5%
B.6%
C.4 1/2%
D.3 1/2 %
Answer: A.5%
Explanation: 160 = (180*4*R)/100
R = 5%
Answer:A
Question: A train overtakes two persons who are walking in the same direction in which the train is going, at the rate of 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively. Find the length of train ?
A.45 m
B.50 m
C.55 m
D.60 m
Answer: B.50 m
Explanation: Explanation:
First person speed = 2*(5/18) = 5/9 m/sec
Second person speed = 4*(5/18) = 10/9 m/sec
Let the length of train is x metre and speed is y m/sec
then,
x /y−5/9=9
=>9y−5=x
=>9y−x=5.....(i)Also,
x /y−10/9=10
90y−9x=100.....(ii)from (i) and (ii), we get,x=50
So length of train is 50 metre
Option B
Question: If the mean of numbers 28, x, 70, 88 and 104 is 67, what is the mean of 50, 62, 97, 124 and x?
A.76.5
B.75.6
C.73.5
D.79
Answer: B.75.6
Explanation: Mean = (Sum of all no. in series)/(no. in series)
M1 = 67 = (X+28+70+88+104)/(5)
67 x 5 = 290 + X
X = 45
Therefore mean of 2nd series
M2 = (X+50+62+97+124)/5
M2 = 75.6
Answer = B
Question: A bag contains 10 red jellybeans and 10 blue jellybeans. If 3 jellybeans are removed one at a time, at random and are not replaced, what is the probability T that all 3 jellybeans removed from the bag are blue?
A.9/100
B.2/19
C.1/8
D.3/20
Answer: B.2/19
Explanation: Method-1
10 red jellybeans and 10 blue jellybeans
Total Outcomes = No. of ways to choose 3 Jelly bean at random out of a total 20 jellybeans = 20C3 = 1140
Favourable Outcomes = No. of ways to choose 3 Jelly bean such that they are all Blue out of 10 Blue = 10C3 = 120
Probability = Favourable Outcomes / Total Outcomes = 10C3 / 20C3
Probability T= 120 / 1140 = 2/19
Answer: option B
Method-2
Probability of First jelly bean to be Blue = 10/20 [Total 10 Blue out of total 20 jellybeans]
Probability of Second jelly bean to be Blue = 9/19 [Total 9 Blue remaining out of total 19 jellybeans remaining]
Probability of Third jelly bean to be Blue = 8/18 [Total 8 Blue remaining out of total 18 jellybeans remaining]
Required Probability = (10/20)*(9/19)*(8/18) = 2/19
Answer: option B
Question: 817 + 8.017 + 0.817 + 8.0017 = ?
A.839.3657
B.833.8357
C.839.6357
D.819.5637
Answer: B.833.8357
Explanation: 817
8.017
0.817
+ 8.0017
--------
833.8357
---------
Answer is B
Question: How many five-digit numbers are there, if the two leftmost digits are even, the other digits are odd and the digit 2 cannot appear more than once in the number.
A.2200
B.2295
C.2375
D.2380
Answer: C.2375
Explanation: N=(4*5-1)*5*5*5=2375
where
4 cases of first digit {2,4,6,8}
5 cases of second digit {0,2,4,6,8}
1 case of 22 for two leftmost digit
5 cases of third digit {1,3,5,7,9}
5 cases of fourth digit {1,3,5,7,9}
5 cases of fifth digit {1,3,5,7,9}
C
Question: Two numbers A and B are such that the sum of 7% of A and 4% of B is two-third of the sum of 6% of A and 8% of B. Find the ratio of A : B.
A.2 : 1
B.1 : 2
C.4 : 9
D.1 : 1
Answer: C.4 : 9
Explanation: Explanation:
7% of A + 4% of B = 2/3(6% of A + 8% of B)
7A/100 + 4B/100 = 2/3(6A/100+8B/100)
⇒7A + 4B = 2/3(6A + 8B)
⇒21A + 12B = 12A + 16B
⇒ 9A = 4B
⇒ AB = 4/9
⇒ A:B=4:9
Answer: Option C