MU-NLPC/Calc-aqua_rat huggingface dataset:
The ratio of flour to water to sugar in a recipe is 7:2:1. The ratio in a new recipe calls for a doubling of the ratio of flour to water from the original recipe and a halving of the ratio of flour to sugar. If the new recipe calls for 2 cups of water, how much sugar is required?  Choose the correct answer
A) 2  B) 3  C) 4  D) 5  E) 6

Solution: The ratio of flour to water is 14:2.   The ratio of flour to sugar is 3.5:1=14:4.   The new ratio of flour to water to sugar is 14:2:4   If we need 2 cups of water, then we need 4 cups of sugar.   The answer is 4.
Answer: C
All the faces of a cube are painted with blue colour. Then it is cut into 125 small equal cubes.
How many small cubes will be formed having only one face coloured ?  Select the correct option:
A) 54  B) 8  C) 16  D) 24  E) 34

Solution: no.of small cubes will have only one face painted=(X-2)2*6   Here x=side of the small cube=5   therfore(X-2)2*6=54   54NSWER:54
Answer: A
A and B entered into a partnership investing Rs.25000 and Rs.30000 respectively. After 4 months C also joined the business with an investment of Rs.35000. What is the share of C in an annual profit of Rs.47000? Choices.
A) 14009
B) 14409
C) 14006
D) 14000
E) 14001

Solution: 25*12: 30*12: 35*8   15:18:14   14/47 * 47000= 
14/47 * 47000 = 14_000
14000   Answer: 14000
Answer: D
A cab driver 5days income was $400, $250, $650, $400 , $500. Then his average income is?	Choose the correct choice from the following answers
A) $400
B) $420
C) $440
D) $460
E) $480

Solution: avg = sum of observations/number of observations   avg income=(400+250+650+400+500)/5= 
(400+250+650+400+500)/5 = 440
440   Answer is $440
Answer: C
A train 50 m long is running with a speed of 68 kmph. In what time will it pass a man who is running at 8 kmph in the same direction in which the train is going?  Choose the correct answer
A) 3 sec. B) 7 sec. C) 9 sec. D) 11 sec. E) None

Solution: Solution   Speed of the train relative to man	=( 68 - 8 )= 
( 68 - 8 ) = 60
60 Kmph= 60 x 5 / 18   =50/3 m/sec.   Time taken by it to cover 50 m at (50 /3)m/sec	= (112 - 50)kmph   = (50 x 3/50)sec   = 3 sec.   3 sec.nswer 3 sec.
Answer: A
15th august 2010 was which day of the week?  Choose the correct choice from the following answers.
A) Thursday B) Friday C) Wednesday D) Sunday E) Monday

Solution: ANSWER: Sunday   Explanation:   15th August 2010 can be written as 2009 + days from 1st January 2010 to 15th August 2010.   => Total number of odd days in 400 years = 0   Hence, total number of odd days in 2000 years = 0 (as 2000 is a perfect multiple of 400)   Odd in days in the period 2001-2009:   7 normal years + 2 leap yeas   => (7*1) + (2*2)= 
(7*1) + (2*2) = 11
11=> Odd days will be 11- (7*1)= 
11- (7*1) = 4
4   Days from January 1 to August 15 in 2010: 31+28+31+30+31+30+31+15= 227 days.   = 32 weeks and 3 days, this gives additional 3 odd days.   => Total odd days= 3+4= 
3+4 = 7
7=> 7 odd days=1 week= 0 odd days   => 0 odd days= Sunday   Thus, 15th August 2010 was a Sunday.   Answer: Sunday
Answer: D
A man swims downstream 72 km and upstream 45 km taking 9 hours each time; what is the speed of the current ?  Choose the correct answer:  A) 2.5 kmph  B) 6.5 kmph  C) 1.5 kmph  D) 8.5 kmph  E) 1.7 kmph

Solution: Explanation:   72 --- 9   ? ---- 1   => Down Stream = 8   45 ---- 9   ? ---- 1   => Up Stream = 5   Speed od current S = ?   S = (8 - 5)/2= 
(8 - 5)/2 = 3/2 = around 1.5
1.5 kmph.   Answer: 1.5 kmph
Answer: C
How many different arrangements of A, B, C, D, and E are possible where A is not adjacent to B ?  Choose the correct choice from the following.
A) 72
B) 48
C) 32
D) 30
E) 1

Solution: So you have 72,B,C,D,E   five possible ways to arrange it = 5! = 120   72B cannot be adjacents   (72B),C,D,E = 4! = 24 x 2(because it can be (72B) or (B72) ) = 48   120 -48- = 72 possible ways   72
Answer: A
Bottle R contains 350 capsules and costs $6.25. Bottle T contains 130 capsules and costs $2.99. What is the difference between the cost per capsule for bottle R and the cost per capsule for bottle T?
Choose the correct answer
A) $0.25 B) $0.12 C) $0.0052 D) $0.003 E) $0.002

Solution: $0.0052ost per capsule in R is 6.25/350=0.0178   $0.0052ost per capsule in T is 2.99/130= 
2.99/130 = 0.023
0.023   The difference is 0.0052   The answer is $0.0052
Answer: C
45 litres of mixture is created by mixing Liquid A and Liquid B in the ratio 3:2. How much more Liquid B must be added to make the ratio 9:11?  Choose the correct choice:
A) 9 Litres
B) 10 Litres
C) 12 Litres
D) 15 Litres
E) 16 Litres

Solution: In current ratio A = (3/5) * 45= 
(3/5) * 45 = 27
27   B is 18   Suppose "b" amount of b is added   new ratio= 27/(b+18) = 9/11   => b+18 = 33   => b = 15   So, answer will be 15 Litres
Answer: D
When 3 fair coins are tossed together, what is the probability of getting 2 tails?
Choose the correct choice.
A) 1/2	B) 1/3	C) 1/4	D) 3/4	E) 2/3

Solution: We can get 2 tails in 3C2 ways.   We can get 3 tails in exactly one way.   Also, there are a total out 8 possible outcomes.   Thus, the required probability = (3 + 1)/8 = 1/2   1/2NSWER:1/2
Answer: A
A certain galaxy is known to comprise approximately 4 x 10^12 stars. Of every 50 million of these stars, one is larger in mass than our sun. Approximately how many stars in this galaxy are larger than the sun?
Choose the correct choice from the following answers
A) 800	B) 1,250	C) 80,000	D) 12,000	E) 80,000

Solution: Total no. of stars on galaxy = 4 * 10^12   Of every 50 million stars, 1 is larger than sun.   1 million = 10^6 therofore, 50 million = 50 * 10^6   total no. of stars larger than sun = 4 * 10^12 / 50 * 10^6   =40 * 10^4 /5   = 80000   therefore answer is 80,000
Answer: C
How long does a train 110 m long running at the speed of 72 km/hr takes to cross a bridge 132 m length? Choose the correct choice from the following options
A) 12.5
B) 12.1
C) 12.9
D) 12.7
E) 12.2

Solution: Speed = 72 * 5/18= 
72 * 5/18 = 20
20 m/sec   Total distance covered= 110 + 132= 
110 + 132 = 242
242 m.   Required time= 242/20= 
242/20 = 121/10 = around 12.1
12.1 sec.   Answer: 12.1
Answer: B
Apple Infotech has 4 Senior Managing Directors and 5 Managing Directors. Each investment banking deal requires the guidance of two managing directors, at least one of which must be a Senior Managing Director. How many possible investment banking deals can Apple Infotech possibly provide guidance for? Choose the correct choice from the following choices:
A) 16  B) 20  C) 26  D) 54  E) 64

Solution: P(at least 1 S D) = P(Total) - P(0 Senior Director)   =9262 - 5262   = 26
Answer: C
Rebecca's annual income is $15, and Jimmy's annual income is $18. By how much must Rebecca's annual income increase so that it constitutes 50% of Rebecca and Jimmy's combined income? Pick one.
A) 7 B) 8 C) 9 D) 3 E) 10

Solution: total rebecca = x+15; total = x+20+18   x+15/x+33 = 50/100 therefore x =3   3
Answer: D
In a ratio which is equal to 4:6, if the antecedent is 50, then the consequent is?  Choose the correct choice from the following options.
A) 75  B) 85  C) 64  D) 51  E) 45

Solution: We have 4/6 = 50/x   4x = 50*6   x = 75   consequent = 75   75nswer is 75
Answer: A
In what ratio must tea at Rs.60 per Kg be mixed with tea at Rs.70 per Kg so that the mixture must be worth Rs.67.5 per Kg?
Pick
A) 3 : 1  B) 3 : 2  C) 4 : 3  D) 1 : 3  E) None

Solution: Required ratio = 250 : 750 = 1 : 3   Answer 1 : 3
Answer: D
Find the simple interest on Rs.500 for 9 months at 6 paisa per month?
Choose one.
A) 288
B) 270
C) 999
D) 278
E) 121

Solution: I = (500*9*6)/100= 
(500*9*6)/100 = 270
270   Answer:270
Answer: B
An old priest fell on a bottom of the well of a church.
The well is 20 inches deep.
At day time, the old priest climbs 5-inches but when at dark he slip back 4 inches.
In how many days priest will come out of the well ?
Choose the most appropriate option:	A) 16-days	B) 14-days	C) 11-days	D) 19-days	E) 10-days

Solution: 16-days   16-days   In 15-days, he will climb 15-inch and when he climbs 5 inch more, he will be out of the well :-)
Answer: A
If Josh, Doug, and Brad have a total of $72 between them, and Josh has three times as much money as Brad but only three-fourths as much as Doug, how much money does Brad have? Choose the correct choice from the following answers:	A) $8	B) $9	C) $27	D) $32	E) $36

Solution: Josh+Doug+Brad = 72 ; Joush = 3 brad, Josh =3/4 doug   Josh+1/3 Josh+ 4/3 Josh = 72 (substituted the given values)   Josh = 27. 27= 3/4 doug => doug =36   Josh+Doug+$9rad = 72   27 + 36 + $9rad = 72   $9rad 27 + 36 +  9= 
27 + 36 +  9 = 72
72   $9rad= 9   Answer is $9.
Answer: B
In a particular year, the month of january had exactly 4 thursdays, and 4 sundays. On which day of the week did january 1st occur in the year.
Pick one.
A) 33
B) Monday
C) 299
D) 299
E) 277

Solution: Ans: If a month has 31 days, and it starts with sunday, Then Sundays, Mondays, tuesdays are 5 for that month. If this month starts with monday, then mondays, tuesdays, and wednesdays are 5 and remaining days are 4 each. so this month start with Monday.   Answer:Monday
Answer: B
If the square root of p^2 is an integer greater than 1, which of the following must be true?
I. p^2 has an odd number of positive factors
II. p^2 can be expressed as the product of an even number of positive prime factors
III. p has an even number of positive factors
Choices:
A) I B) II C) III D) I and II E) II and III

Solution: It is given that p2−−√p2>1 and is an integer..   Also p2−−√p2=p   so p^2 is a perfect square and p is an integer>1..   lets see three statements:-   I. p^2 has an odd number of positive factors-- TRUE   A perfect square has an Odd number of perfect square ..   WHY? Because all factors will have a different integer as a pair except p..   p*p=p^2.. so that will be just one factor   II. p^2 can be expressed as the product of an even number of positive prime factors   again TRUE   25 =5*5 ; 49= 7*7 ; 36 = 2*2*3*3   III. p has an even number of positive factors..   Since it uses 'HAS', if we find one which does not follow the statement is not true..   we already know that A perfect square has an Odd number of perfect square ..   so if p is a perfect square itself ans is No   ONLY I and II are true   ANSWER:I and II
Answer: D
Which of the below fractions has the highest value?	Select the correct option:  A) A)23/77  B) B)23/78  C) C)23/84  D) D)23/87  E) E)23/40

Solution: 23/40.   Now, all options have the same numerator 23. If numerator is same, the fraction with the highest value will be the one with the lowest denominator.   Answer (23/40).
Answer: E
A discount electronics store normally sells all merchandise at a discount of 10 percent to 30 percent off the suggested retail price. If, during a special sale, an additional 25 percent were to be deducted from the discount price, what would be the lowest possible price of an item costing $260 before any discount?
Choose the correct option.
A) $136.50
B) $145.60
C) $163.80
D) $182.00
E) $210.00

Solution: Since the question is essentially just about multiplication, you can do the various mathstepsin a variety of ways (depending on whichever method you find easiest).   We're told that the first discount is 10% to 30%, inclusive. We're told that the next discount is 25% off of the DISCOUNTED price....   We're told to MAXIMIZE the discount (thus, 30% off the original price and then 20% off of the discounted price). Thatmathcan be written in a number of different ways (fractions, decimals, etc.):   30% off = (1 - .3) = (1 - 30/100) = (.7) and the same can be done with the 20% additional discount...   The final price of an item that originally cost $260 would be.....   ($260)(.7)(.75) =   ($260)(.525)=136.5   Final $136.50nswer:   $136.50
Answer: A
he ratio between the sale price and the cost price of an article is 4:7. What is the ratio between the profit and the cost price of that article?  Choose the correct choice from the following:
A) 2:6  B) 3:7  C) 3:8  D) 2:1  E) 8:3

Solution: Let C.P. = Rs. 7x and S.P. = Rs. 4x.   Then, Gain = Rs. 3x   Required ratio = 3x : 7x = 3:7.   Answer:3:7
Answer: B
In year Y imported machine tools accounted for 25 percent of total machine-tools sales in the United States, and Japanese imports accounted for 40 percent of the sales of imported machine tools. If the total sales of machine tools imported from Japan that year was x billion dollars, then the total sales of all machine tools in the United States was how many billion dollars?
Choose the correct choice from the following choices
A) 9x/80	B) 13x/20	C) 80/9x	D) 10x	E) 80x/9

Solution: Sales of imported tools = 25% of the total sales = 0.25*{total} = {total}/4;   Sales of Japanese tools = 40% of the sales of imported tools = 0.40*{total}/4 = 2/5*{total}/4 = 2*{total}/20.   Since the sales of of Japanese tools was x, then 2*{total}/20 = x --> {total} = 10x.   Answer: 10x.
Answer: D
The average of first ten prime numbers which are odd is?  Select
A) 15.7  B) 15.0  C) 15.2  D) 15.8  E) 15.1

Solution: Sum of first 10 prime no. which are odd = 158   Average = 158/10= 
158/10 = 79/5 = around 15.8
15.8   Answer: 15.8
Answer: D
If 1 kilometer is approximately 0.6 mile, which of the following best approximates the number of kilometers in 7 miles?  Select the correct option
A) 22/5 B) 20/5 C) 15/5 D) 21/5 E) 16/4

Solution: 1 km is approxmately equal to 0.6 miles   So 7 km = 7*0.6= 
7*0.6 = 4.2
4.2 miles . Multiple & divide by 10   i.e 4.2*10/10= 42/10 = 21/5   Answer : 21/5
Answer: D
A person’s age is 125% of what it was one decade ago, but 83(1/3)% of what it will be after one decade. What is his current age? [1 decade = 10 years] Choose the correct choice from the following answers:
A) 50 years
B) 60 years
C) 30 years
D) 70 years
E) 80 years

Solution: A   50 years   Let, current age is A years.   Then, 125% of (50 years – 10) = 50 years   and, 83(1/3)% of (50 years + 10) = 50 years   Therefore 125% of (50 years-10) = 83(1/3)% of (50 years+10)   or, (5/4) (50 years – 10) =(5/6)(50 years+10)   or, (5/4)50 years -(5/6)50 years = (50/6)+(50/4)   or, (550 years/12)= (250/12) or,   50 years=50 years.
Answer: A
A student took five papers in an examination, where the full marks were the same for each paper. His marks in these papers were in the proportion of 6 : 7 : 8 : 9 : 10. In all papers together, the candidate obtained 60% of the total marks. Then the number of papers in which he got more than 61% marks is	Choose the correct choice from the following answers
A) 6
B) 5
C) 4
D) 3
E) 2

Solution: Here we can assume that one subject is of 100 marks so total there are 5 subjects => 100*5= 
100*5 = 500
500.   Now according to the question he secured 60 % of those which is 60%of 500= 300 marks in total.   The ratio between the marks is given as 6 : 7 : 8 : 9 : 10 , so now we can distribute 300 marks according to the ratio.   Total ratio = 40   For 6 : (300/40)*6= 
(300/40)*6 = 45
45   Similarly , we will get for others as 52.5 , 60 , 62.5 , 75.   Hence , there are 2 subject where he secured more that 50 %.   The answer is 2.   2
Answer: E
If n = 14p, where p is a prime number greater than 2, how many different positive even divisors does n have, including n ?
Answers
A) Two
B) Three
C) Four
D) Six
E) Eight

Solution: If n = 14p, where p is a prime number greater than 2, how many different positive even divisors does n have, including n ?   (A) Two   (B) Three   (C) Four   (D) Six   (E) Eight   Since we cannot have two correct answers just pick a prime greater than 2, and see how many different positiveevendivisors will 14p have.   p = 3 --> 14p = 42--> 42 has 4 even divisors: 2, 6, 14, 42 .   Answer: Four.
Answer: C
In a stack of boards at a lumber yard, the 20th board counting from the top of the stack is immediately below the 17th board counting from the bottom of the stack. How many boards are in the stack?  Pick one:
A) 38	B) 36	C) 35	D) 34	E) 32

Solution: Counting from the top, after the 20th board, there are 15 boards left to count.   The answer is 35.
Answer: C
A man is standing on a railway bridge which is 240 m long. He finds that a train crosses the bridge in 20 seconds but himself in 8 seconds. Find the length of the train and its speed.
Choose the correct answer:
A) 10 m/sec
B) 15 m/sec
C) 18 m/sec
D) 20 m/sec
E) 25 m/sec

Solution: If length of train is l and speed of train is s, then   l/s = 8   (l+240)/s = 20   (l+240)/l = 20/8 =5/2   2l+480 =5*l   3*l= 480   l=160 mtrs   s= l/8 = 160/8= 
160/8 = 20
20 m/sec   ANSWER:20 m/sec
Answer: D
For one toss of a certain coin, the probability that the outcome is heads is 0.3. If this coin is tossed 5 times, which of the following is the probability that the outcome will be heads at least 4 times?	Choose the correct choice from the following
A) (0.3)^5	B) 2(0.3)^4	C) 3(0.3)^4	D) 4(0.3)^4(0.7) + (0.3)^5	E) 5(0.3)^4(0.7) + (0.3)^5

Solution: P(5 heads) = (0.3)^5   There are 5 ways to get 4 heads: HHHHT, HHHTH, HHTHH, HTHHH, THHHH   P(4 heads) = 5*(0.3)^4(0.7)   The answer is 5(0.3)^4(0.7) + (0.3)^5.
Answer: E
A train traveled the first d miles of its journey it an average speed of 50 miles per hour, the next d miles of its journey at an average speed of y miles per hour, and the final d miles of its journey at an average speed of 160 miles per hour. If the train’s average speed over the total distance was 96 miles per hour, what is the value of y?	Answers.
A) 68
B) 84
C) 90
D) 120
E) 160

Solution: Average speed=Total distance traveled /Total time taken   3d/d/50+d/y+d/160=96   Solving for d and y,   15y=11y+480   3y=480   y=160   Answer 160
Answer: E
If 75 percent of a girls answered the first question on a certain test correctly, 55 percent answered the second question on the test correctly, and 20 percent answered neither of the questions correctly, what percent answered both correctly?	Select:  A) 10%  B) (8) 20%  C) 30%  D) 40%  E) 50%

Solution: {Total} = {First} + {Second} - {Both} + {Neither}   100% = 75% + 55% - {Both} + 20% --> {Both} = 50%.   Answer: 50%.
Answer: E
A certain quantity is measured on two different scales, the T-scale and the S-scale, that are related linearly. Measurements on the T-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the T-scale corresponds to a measurement of 100 on the S-scale? Choices
A) 20  B) 36  C) 48  D) 60  E) 84

Solution: First, we have to understand what linearly means. It's not a straight ratio (since 6:30 does NOT equal 24:60). We need to look at the increases in each measurement to see what the scalar actually is.   From 6 to 24 we have an increase of 18. From 30 to 60 we have an increase of 30. Therefore, the increase ratio is 18:30 or 3:5. In other words, for every 3 that T increases, S increases by 5.   We know that S is 100. To get from 60 to 100, we went up by 40, or 8 jumps of 5; therefore, T will go up by 8 jumps of 3.   24 + 8(3) = 24 + 24= 
24 + 24 = 48
48=48
Answer: C
A, B and C can do a piece of work in 24, 30 and 40 days respectively. They start the work together but C leaves 4 days before the completion of the work. In how many days is the work done?	Choose the correct choice from the following answers:	A) 11 days	B) 14 days	C) 13 days	D) 10 days	E) 20 days

Solution: x/24 + x/30 + x/40 = 1   x = 11 days   11 daysNSWER 11 days
Answer: A
Set A {3,3,3,4,5,5,5} has a standard deviation of 1. What will the standard deviation be if every number in the set is multiplied by 8? Choose one:
A) A)1
B) B)2
C) C)4
D) D)8
E) E)16

Solution: Points to remember -   1. If oneAdd/Subtractthe same amont from every term in a set, SD doesn't change.   2. If oneMultiply/Divideevery term by the same number in a set, SD changes by same number.   Hence the answer to the above question is 8
Answer: D
A thief is noticed by a policeman from a distance of 300 m. The thief starts running and the policeman chases him. The thief and the policeman run at the rate of 10 km and 11 km per hour respectively. What is the distance between them after 6 minutes?	Select
A) 150 m  B) 200 m  C) 170 m  D) 100 m  E) 250 m

Solution: Relative speed of the thief and policeman = 11 - 10= 
11 - 10 = 1
1 km/hr.   Distance covered in 6 minutes= 1/60 * 6 = 1/10 km = 100 m.   Distance between the thief and policeman = 300 - 100= 
300 - 100 = 200
200 m   200 m
Answer: B
The jogging track in a sports complex is 660 m in circumference. Deepak and his wife start from the same point and walk in opposite directions at 4.5 km/hr and 3.75 km/hr respectively. They will meet for the first time in?
Choose the correct choice from the following options.
A) 5.29 min	B) 5.28 min	C) 5.08 min	D) 4.8 min	E) 5.988 min

Solution: Clearly, the two will meet when they are 660 m apart.   To be (4.5 + 3.75)= 
(4.5 + 3.75) = 8.25
8.25 km apart, they take 1 hour.   To be 660 m apart, they take (100/825 * 660/1000) hrs= (660/8250 * 60)= 
(660/8250 * 60) = 24/5 = around 4.8
4.8 min.   Answer: 4.8 min
Answer: D
If 30% of a number is 12.6, find the number?  Pick.
A) 42
B) 40
C) 26
D) 36
E) 66

Solution: 42   40
Answer: A
During a trip, Francine traveled x percent of the total distance at an average speed of 100 miles per hour and the rest of the distance at an average speed of 90 miles per hour. In terms of x, what was Francineâ€™s average speed for the entire trip?	Options:
A) (180-x)/2 B) (x+60)/4 C) (300-x)/5 D) 600/(115-x) E) 9,000/(100+8x)

Solution: E....   X% traveeled at 10 mph   100-X% traveeled at 90 mph   total timt taken = x/10 +(100-x)/90 = (100+8x)/90   Total distance = x+(100-x) = 100   Av speed = Tot Dis/Time Taken which is 9,000/(100+8x)
Answer: E
If the wheel is 14 cm then the number of revolutions to cover a distance of 1056 cm is?	Options:  A) 18  B) 26  C) 14  D) 12  E) 91

Solution: 2 * 22/7 * 14 * x = 1056 => x   = 12   Answer: 12
Answer: D
Find the simple interest for Rs. 2000 at 8% p/a for 2years.  Choose the correct choice from the following options.
A) Rs.300  B) 3Rs.20  C) Rs.420  D) Rs.520  E) Rs.460

Solution: S.I= (2000*8*2)/100= 
(2000*8*2)/100 = 320
320   Answer: 3Rs.20
Answer: B
Which of the following is larger than 3/5?  Pick one: A) 1/2 B) 39/50 C) 7/25 D) 3/10 E) 59/100

Solution: if we want to compare two fraction number   a/b =c/d   then a*d (answer to a/b)   c*b (ans to c/d) (apply this conditions to all the options)   Therefore (3*5=15) (39*5=195)   39/5 is greater than 3/5..   ANSWER:39/50
Answer: B
A father was as old as his son's present at the time of your birth. If the father's age is 34 years now, the son's age 5years back was?	Options.
A) 10 years  B) 12 years  C) 14 years  D) 16 years  E) 20 years

Solution: Let the son's present age be x years. Then, (34 - x) = x   2x = 34.   x = 17.   Son's age 5 years back (17 - 5)= 
(17 - 5) = 12
12 years.   12 years
Answer: B
At a contest with 3,500 participants, 1/2 of the people are aged 18 to 22. Next year, the number of people aged 18 to 22 will increase by 1/7. After this change, what percentage of the total 3,500 people will the 18- to 22-year-olds represent?
Options: A) 33% B) 40% C) 55% D) 57.14% E) 66.14%

Solution: I just wanted to mention a couple of things here:   * this is a pure ratio question; the number 3,500 is completely irrelevant, and you can ignore it if you like. When we increase something by 1/7, we are multiplying it by 1 + 1/7 = 8/7, so the answer here must be (1/2)*(8/7) = 4/7 = 57.14 %.   Answer : 57.14%
Answer: D