World History Questions Answers (MCQ) listing of General Intelligence is important for General Knowledge of SSC CGL, UPSC, IBPS, MAT, CAT and other competitive exams.

1) Worker A takes 8 hours to do a job. Worker B takes 10 hours to do a job. How long should it take both A and B, working together to do same jo

• 1) \begin{aligned} \frac{4}{9} \end{aligned}
• 2) \begin{aligned} 2\frac{4}{9} \end{aligned}
• 3) \begin{aligned} 3\frac{4}{9} \end{aligned}
• 4) \begin{aligned} 4\frac{4}{9} \end{aligned}
Ans.   D
Explanation :
In this type of questions, first we need to calculate 1 hours work, then their collective work as, A's 1 hour work is 1/8 B's 1 hour work is 1/10 (A+B)'s 1 hour work = 1/8 + 1/10 = 9/40 So both will finish the work in 40/9 hours = \begin{aligned} 4\frac{4}{9} \end{aligned}

2) A can finish a work in 18 days and B can do same work in half the time taken by A. then working together, what part of same work they can finish in a d

• 1) 1\5
• 2) 1\6
• 3) 1\7
• 4) 1\8
Ans.   B
Explanation :
Please note in this question, we need to answer part of work for a day rather than complete work. It was worth mentioning here because many do mistake at this point in hurry to solve the question So lets solve now, A's 1 day work = 1/18 B's 1 day work = 1/9 [because B take half time than A] (A+B)'s one day work = \begin{aligned} \left(\frac{1}{18}+\frac{1}{9} \right) \\ =\left(\frac{1+2}{18} \right) \\ = \frac{1}{6} \end{aligned} So in one day 1/6 work will be done.

3) A does a work in 10 days and B does the same work in 15 days. In how many days they together will do the same work

• 1) 5 days
• 2) 6 days
• 3) 7 days
• 4) 8 days
Ans.   B
Explanation :
Firstly we will find 1 day work of both A and B, then by adding we can get collective days for them, So, A's 1 day work = 1/10 B's 1 day work = 1/15 (A+B)'s 1 day work = \begin{aligned} \left(\frac{1}{10}+\frac{1}{15} \right) \=\left(\frac{3+2}{30} \right) \= \frac{1}{6} \end{aligned} So together they can complete work in 6 days.

4) A and B can together complete a piece of work in 4 days. If A alone can complete the same work in 12 days, in how many days can B alone complete that work

• 1) 4 days
• 2) 5 days
• 3) 6 days
• 4) 7 days
Ans.   C
Explanation :
(A+B)'s 1 day work = 1/4 A's 1 day work = 1/12 B's 1 day work = \begin{aligned} \left( \frac{1}{4} - \frac{1}{12} \right) \= \frac{3-1}{12} \= \frac{1}{6} \\end{aligned} So B alone can complete the work in 6 days

5) A tyre has two punctures. The first puncture alone would have made the tyre flat in 9 minutes and the second alone would have done it in 6 minutes. If air leaks out at a constant rate, how long does it take both the punctures together to make it flat

• 1) \begin{aligned} 3\frac{1}{5} min \end{aligned}
• 2) \begin{aligned} 3\frac{2}{5} min \end{aligned}
• 3) \begin{aligned} 3\frac{3}{5} min \end{aligned}
• 4) \begin{aligned} 3\frac{4}{5} min \end{aligned}
Ans.   C
Explanation :
Do not be confused, Take this question same as that of work done question's. Like work done by 1st puncture in 1 minute and by second in 1 minute. Lets Solve it: 1 minute work done by both the punctures = \begin{aligned} \left(\frac{1}{9}+\frac{1}{6} \right) \\ =\left(\frac{5}{18} \right) \\ \end{aligned} So both punctures will make the type flat in \begin{aligned} \left(\frac{18}{5} \right)mins \\ = 3\frac{3}{5} mins \end{aligned}

6) A man can do a piece of work in 5 days, but with the help of his son he can do it in 3 days. In what time can the son do it alone

• 1) \begin{aligned} 7\frac{1}{2}days \end{aligned}
• 2) \begin{aligned} 6\frac{1}{2}days \end{aligned}
• 3) \begin{aligned} 5\frac{1}{2}days \end{aligned}
• 4) \begin{aligned} 4\frac{1}{2}days \end{aligned}
Ans.   A
Explanation :
In this type of question, where we have one person work and together work done. Then we can easily get the other person work just by subtracting them. As, Son's one day work = \begin{aligned} \left(\frac{1}{3}-\frac{1}{5} \right) \\ =\left(\frac{5-3}{15} \right) \\ = \frac{2}{15} \end{aligned} So son will do whole work in 15/2 days which is = \begin{aligned} 7\frac{1}{2}days \end{aligned}

7) A is twice as good as workman as B and together they finish a piece of work in 18 days. In how many days will B alone finish the wor

• 1) 27 days
• 2) 54 days
• 3) 56 days
• 4) 68 days
Ans.   B
Explanation :
As per question, A do twice the work as done by B. So A:B = 2:1 Also (A+B) one day work = 1/18 To get days in which B will finish the work, lets calculate work done by B in 1 day = \begin{aligned} =\left(\frac{1}{18}*\frac{1}{3} \right) \\ = \frac{1}{54} \end{aligned} [Please note we multiplied by 1/3 as per B share and total of ratio is 1/3] So B will finish the work in 54 days

8) A can do a job in 16 days, B can do same job in 12 days. With the help of C they did the job in 4 days. C alone can do the same job in how many days

• 1) \begin{aligned} 6\frac{1}{2}days \end{aligned}
• 2) \begin{aligned} 7\frac{1}{2}days \end{aligned}
• 3) \begin{aligned} 8\frac{3}{5}days \end{aligned}
• 4) \begin{aligned} 9\frac{3}{5}days \end{aligned}
Ans.   D
Explanation :
In this question we having, A's work, B's work and A+B+C work. We need to calculate C's work. We can do it by, (A+B+C)'s work - (A's work + B's work). Let's solve it now: C's 1 day work = \begin{aligned} \frac{1}{4}- \left(\frac{1}{16} +\frac{1}{12} \right) \\ =\left(\frac{1}{4} - \frac{7}{48} \right) \\ = \frac{5}{48} \end{aligned} So C can alone finish the job in 48/5 days, Which is = \begin{aligned} 9\frac{3}{5}days \end{aligned}

9) To complete a work A and B takes 8 days, B and C takes 12 days, A,B and C takes 6 days. How much time A and C will ta

• 1) 24 days
• 2) 16 days
• 3) 12 days
• 4) 8 days
Ans.   D
Explanation :
A+B 1 day work = 1/8 B+C 1 day work = 1/12 A+B+C 1 day work = 1/6 We can get A work by (A+B+C)-(B+C) And C by (A+B+C)-(A+B) So A 1 day work = \begin{aligned} \frac{1}{6}- \frac{1}{12} \\ = \frac{1}{12} \end{aligned} Similarly C 1 day work = \begin{aligned} \frac{1}{6}- \frac{1}{8} \\ = \frac{4-3}{24} \= \frac{1}{24} \end{aligned} So A and C 1 day work = \begin{aligned} \frac{1}{12} + \frac{1}{24} \\ = \frac{3}{24} \= \frac{1}{8} \end{aligned} So A and C can together do this work in 8 days

10) A does half as much work as B in three-fourth of the time. If together they take 18 days to complete the work, how much time shall B take to do

• 1) 40 days
• 2) 35 days
• 3) 30 days
• 4) 25 days