The ones who are crazy enough to think they can change the world are the ones who do.

- Steve Jobs

Time and Work Interview Questions

Time and Work - Aptitude

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?

x

Option: B

Explanation

son's 1 day's work = (1/3) - (1/5) = 2/15

i.e) the son alone can do the work in 15/2 days

✉ Answer

7.A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With the help of C, they did the job in 4 days only. Then, C alone can do the job in:

x

Option: A

Explanation

(A + B + C)'s 1 day's work = 1/4

A's 1 day's work = 1/16

B's 1 day's work = 1/12

C's 1 day's work = (1/4) - ((1/16) + (1/12)) = (1/4) - (7/48) = 5/48

so, C alone can do the work in 48/5 days

✉ Answer

8.A takes twice as much time as B or thrice as much time to finish a piece of work.Working together, they can finish the work in 2 days. B can do the work alone in:

x

Option: B

Explanation

suppose A, B and C take x, x/2 and x/3 hrs respectively to finish the work

then, (1/x) + (2/x) + (3/x) = 1/2

.i.e. 6/x = 1/2

x = 12 hrs, B = x/2 = 12/2 = 6 hrs

✉ Answer

9.Harrison and Jade are working on an assignment. Harrison takes 6 hrs to type 32 pages on a computer, while Jade takes 5 hrs to type 40 pages. How much time will they take, working together on two different computers to type an assignment of 110 pages?

x

Option: D

Explanation

number of pages typed by Harrison in 1 hr = 32/6 = 16/3

number of pages typed by Jade in 1 hr = 40/5 = 8

number of pages typed by both in 1 hr = (16/3) + 8 = 40/3

Time taken by both to type 110 pages = (110) * (3/40)hrs = 33/4 hrs = 8 hrs 15 min

✉ Answer

10.P can complete a work in 12 days working 8 hrs a day. Q can complete the same work in 8 days working 10 hrs a day. If both P and Q work together, working 8 hrs a day, in how many days can they complete the work?