Important Questions on Time and Work for IBPS Bank PO Exam

Important Facts and Formulae
  1. If A can do a piece of work in n days then A’s 1 day’s work =1/n
  2. If A’s 1 day’s work=1/n, then A can finish the work in n days.
  3. If A is thrice as good as workman as B,then:
  • Ratio of work done by A and B = 3:1
  • Ratio of times taken by A and B to finish a Work =1:3

(1)P can complete a work in 12 days working 8 hours a day.Q can complete the same work in 8 days working 10 hours a day.If both P and Q work together,working 8 hours a day,in How many days can they complete the work?(Asked in Bank PO Exam 1999)

  • 60/11
  • 61/11
  • 71/11
  • 72/11
(2)A and B can do a work in 12 days,B and C can do the same work in 12 days.A,B and C together can finish it in 6 days.A and C together will do it in:
  • 5 days
  • 47/6 days
  • 10 days
  • 47/3 days
(3)A and B can do a work in 8 days,B and C can do the same work in 12 days.A,B and C together can finish it in 6 days.A and C together will do it in:
  • 4 days
  • 6 days
  • 8 days
  • 12 days
(4)A and B can do a piece of work in 72 days,B and C can do it in 120 days,A and C can do it in 90 days.In what time can A alone do it?
  • 80 days
  • 100 days
  • 120 days
  • 150 days
(5)A works twice as fast as B.If B can complete a work in 12 days independently,the number of days in which A and B can together finish the work is:
  • 4 days
  • 6 days
  • 8 days
  • 18 days
(6)A is thrice as good a workman as B and therefore is able to finish a job in 60 days less than B.Working together,they can do it in:
  • 20 days
  • 45/2 days
  • 25 days
  • 30 days
(7)A and B can do a job together in 7 days.A is 7/4 times as efficient as B.The same job can be done by A alone in:
  • 28/3
  • 11 days
  • 49/4
  • 49/3
(8)A can do  a work in 15 days and B in 20 days.If they work on it together for 4 days,then the fraction of the work that is left is:
  • 1/4
  • 1/10
  • 7/15
  • 8/15
(9)X and Y can do a piece of work in 20 days and 12 days respectively.X started the work alone and then after 4 days Y joined him till the completion of the work.How long did the work last?(bank Po 2004)
  • 6 days
  • 10 days
  • 15 days
  • 20 days
(10)A and B can do a piece of work in 30 days,while B and C can do the same work in 24 days and C and A in 20 days.They all work together for 10 days when B and C leave.How many days more will A take to finish the work?
  • 18 days
  • 24 days
  • 30 days
  • 36 days
Answers
Question Number Answer
1 60/11
2 10 days
3 8 days
4 120 days
5 4 days
6 45/2 days
7 11 days
8 8/15
9 10 days
10 18 days