# World History Questions Answers

11) A is thrice as good a workman as B and takes 10 days less to do a piece of work than B takes. B alone can do the whole work

- 1) 15 days
- 2) 10 days
- 3) 9 days
- 4) 8 days

**Ans.**A

**Explanation :**

Ratio of times taken by A and B = 1:3 Means B will take 3 times which A will do in 1 time If difference of time is 2 days, B takes 3 days If difference of time is 10 days, B takes (3/2) * 10 =15 days

12) A can do a piece of work in 15 days and B alone can do it in 10 days. B works at it for 5 days and then leaves. A alone can finish the remaining work

- 1) 5 days
- 2) 6 days
- 3) 7.5 days
- 4) 8.5 days

**Ans.**C

**Explanation :**

B's 5 days work = \begin{aligned} \frac{1}{10}*5 = \frac{1}{2} \ \text{Remaining work =} 1-\frac{1}{2} \ = \frac{1}{2} \ \text{A can finish work =}15*\frac{1}{2} \= 7.5 days \end{aligned}

13) A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid t

- 1) Rs. 300
- 2) Rs. 400
- 3) Rs. 500
- 4) Rs. 600

**Ans.**B

**Explanation :**

C's 1 day's work = \begin{aligned} \frac{1}{3}- \left(\frac{1}{6} +\frac{1}{8} \right) \\ =\left(\frac{1}{3} - \frac{7}{24} \right) \\ = \frac{1}{24} \A:B:C = \frac{1}{6}:\frac{1}{8}:\frac{1}{24} \= 4:3:1 \C's Share = \frac{1}{8}* 3200 \ = 400 \end{aligned} If you are confused how we multiplied 1/8, then please study ratio and proportion chapter, for small information, it is the C ratio divided by total ratio.

14) 4 men and 6 women finish a job in 8 days, while 3 men and 7 women finish it in 10 days. In how many days will 10 women working together finish i

- 1) 30 days
- 2) 40 days
- 3) 50 days
- 4) 60 days

**Ans.**B

**Explanation :**

Let 1 man's 1 day work = x and 1 woman's 1 days work = y. Then, 4x + 6y = 1/8 and 3x+7y = 1/10 solving, we get y = 1/400 [means work done by a woman in 1 day] 10 women 1 day work = 10/400 = 1/40 10 women will finish the work in 40 days

15) A completes 80% of a work in 20 days. Then B also joins and A and B together finish the remaining work in 3 days. How long does it need for B if he alone completes the wo

- 1) \begin{aligned} 35\frac{1}{2} \end{aligned}
- 2) \begin{aligned} 36\frac{1}{2} \end{aligned}
- 3) \begin{aligned} 37\frac{1}{2} \end{aligned}
- 4) \begin{aligned} 38\frac{1}{2} \end{aligned}

**Ans.**C

**Explanation :**

Work done by A in 20 days = 80/100 = 8/10 = 4/5 Work done by A in 1 day = (4/5) / 20 = 4/100 = 1/25 --- (1) Work done by A and B in 3 days = 20/100 = 1/5 (Because remaining 20% is done in 3 days by A and B) Work done by A and B in 1 day = 1/15 ---(2) Work done by B in 1 day = 1/15 â€“ 1/25 = 2/75 => B can complete the work in 75/2 days = 37 (1/2) days

16) A piece of work can be done by 6 men and 5 women in 6 days or 3 men and 4 women in 10 days. It can be done by 9 men and 15 women in how many day

- 1) 3 days
- 2) 4 days
- 3) 5 days
- 4) 6 days

**Ans.**A

**Explanation :**

To calculate the answer we need to get 1 man per day work and 1 woman per day work. Let 1 man 1 day work =x and 1 woman 1 days work = y. => 6x+5y = 1/6 and 3x+4y = 1/10 On solving, we get x = 1/54 and y = 1/90 (9 men + 15 women)'s 1 days work = (9/54) + (15/90) = 1/3 9 men and 15 women will finish the work in 3 days

17) A can do a piece of work in 4 hours . A and C together can do it in just 2 hours, while B and C together need 3 hours to finish the same work. In how many hours B can complete the wor

- 1) 10 hours
- 2) 12 hours
- 3) 16 hours
- 4) 18 hours

**Ans.**B

**Explanation :**

Work done by A in 1 hour = 1/4 Work done by B and C in 1 hour = 1/3 Work done by A and C in 1 hour = 1/2 Work done by A,B and C in 1 hour = (1/4)+(1/3) = 7/12 Work done by B in 1 hour = (7/12)â€“(1/2) = 1/12 => B alone can complete the work in 12 hour

18) A alone can complete a work in 16 days and B alone can do in 12 days. Starting with A, they work on alternate days. The total work will be completed

- 1) \begin{aligned} 13\frac{1}{4} \end{aligned}
- 2) \begin{aligned} 13\frac{1}{2} \end{aligned}
- 3) \begin{aligned} 13\frac{3}{4} \end{aligned}
- 4) \begin{aligned} 13\frac{4}{4} \end{aligned}

**Ans.**C

**Explanation :**

A's 1 day work = 1/16 B's 1 day work = 1/12 As they are working on alternate day's So their 2 days work = (1/16)+(1/12) = 7/48 [here is a small technique, Total work done will be 1, right, then multiply numerator till denominator, as 7*6 = 42, 7*7 = 49, as 7*7 is more than 48, so we will consider 7*6, means 6 pairs ] Work done in 6 pairs = 6*(7/48) = 7/8 Remaining work = 1-7/8 = 1/8 On 13th day it will A turn, then remaining work = (1/8)-(1/16) = 1/16 On 14th day it is B turn, 1/12 work done by B in 1 day 1/16 work will be done in (12*1/16) = 3/4 day So total days = \begin{aligned} 13\frac{3}{4} \end{aligned} It may be a bit typical question, but if are not getting it in first try then give it a second try. Even not, then comment for explanation for this. We will be happy to help you.

19) 10 women can complete a work in 7 days and 10 children take 14 days to complete the work. How many days will 5 women and 10 children take to complete the wo

- 1) 6 days
- 2) 7 days
- 3) 8 days
- 4) 9 days

**Ans.**B

**Explanation :**

1 woman's 1 day's work = 1/70 1 Child's 1 day's work = 1/140 5 Women and 10 children 1 day work = \begin{aligned} \left(\frac{5}{70}+\frac{10}{140}\right) \ = \frac{1}{7} \end{aligned} So 5 women and 10 children will finish the work in 7 days.

20) 5 men and 2 boys working together can do four times as much work as a man and a boy. Working capacity of man and boy is in the ra

- 1) 1:2
- 2) 1:3
- 3) 2:1
- 4) 2:3

**Ans.**C

**Explanation :**

Let 1 man 1 day work = x 1 boy 1 day work = y then 5x + 2y = 4(x+y) => x = 2y => x/y = 2/1 => x:y = 2:1