Question: A is 30% more efficient than B. They can complete the work in 39 days if work together. In how many days, A can complete that work alone.
There is a simple Shortcut trick through which you can solve this type of questions quickly and easily. In this type of time and work questions, follow the steps given below.
A 30% more efficient means if B can do a work in 10 days then A will do it in 13 days.
So time taken by both (in terms of efficiency) will be 10+13=23
So A will complete the work in Total time x time taken to complete the work doing together)/time taken by A(because it is asked in question)
So time taken by A= (23×39)/13=69 days
If time taken by B alone is asked then
B will complete the work in Total time x time taken to complete the work doing together)/time taken by B
And the answer becomes
B will complete the work in 23×39/10= 89.7 days
Remember A 10% more efficient than B means A=11, B=10
A 20% more efficient than B means A=12, B=10
A 50% more efficient than B means A=15, B=10
B 10% more efficient than A means A=10, B=11
Hope you know this time and work trick basics now.
Lets move on to another type of question.
QUESTION: A work is scheduled to be completed in 45 days. 150 men were initially appointed to do the work. After 30 days, 100 more men were appointed such that the work got completed on time. If they were not appointed, then in how many extra days, the work would have completed?
Here is a simple, quick and easy time and work shortcut trick for this type of question.
Just multiply extra appointed people to the time they worked and divide with initial number of people.
So extra days the work would have taken= (100×15)/150= 10 days extra