Time and Work Problem

Time and Work Problem Tricks

Time and work is most trending topic in aptitude of all type of exams. Here we discuss about all shortcuts, tips and tricks related to time and work topic.

Work : is defined as something which has an effect or outcome; often the one desired or expected.

Note: Work (Efficiency) is inversely proportional to the Time taken when the amount of work done is constant.

Rule: If A can do a piece of work in D days, then A's 1 day's work = 1/D

Rule: If A's work efficiency is 2 times as compared to B then Ratio of work done by A and B is 2 :1 Ratio of times taken by A and B to finish a work = 1 : 2 (inverse ratio)

Rule: Let M1 person can do W1 work in D1 days with time T1 and M2 person can do W2 work in D2 days with time T2, then the relationship can be written as

 
 M1D1T1W2 = M2D2T2W1

Rule: If A, B and C can do a work in x, y and z days respectively then all of them working together can finish the work in

 
XYZ / XY+YZ+XZ number of days

 
Total work = No of days * Efficiency.

Question 1: Ram will do a piece of work in 15 days, what part of work will he do in two days ?

 
1 day work's done by Ram = 1/15
so, 2 days work by Ram = 2* 1/15
=2/15

Question 1: 12 men can complete a work in 8 days. 16 women can complete the same work in 12 days. 8 men and 8 women started working and worked for 6 days. How many more men are to be added to complete the remaining work in 1 day?

Answer: (B) 12

• (A) 15
• (B) 12
• (C) 8
• (D) 10

 
1 man's 1 day work =1/96 ; 1 woman's 1 day work = 1/192
Work done in 6 days = 6 (8/96 + 8/192) = 6 * 1/8 = 3/4
Remaining work = 1/4
(8 men +8 women)'s 1 day work = 1 (8/96 + 8/192) = 1/8
Remaining work =1/4 -  1/8 = 1/8
1/96 work is done in 1 day by 1 man
Therefore, 1/8 work will be done in 1 day by 96 x (1/8) =12 men