This time, we are posting Time and work problems type #6 as a part of the series. As said earlier, there are approximately more than 20 types of time and work problems from which there are some questions that can be asked in SSC, IBPS or other competitive exams.

Suppose you are given a question like the one given below:

Q: A can do a piece of work in 15 days but if B helps him, he can finish the work in 10 days. Determine in how many days, B can finish that work working alone?

Shortcut method for solving this question is given below:

Given

A=15 days

And

A+B=10 days

Step 1.

Take LCM of 15 and 10 by shortcut of LCM. The LCM will be 30 which is total work.

Step 2. Divide this LCM i.e. 30 by 15 and 10 respectively. The values comes out are A’s and A+B’s one day work capacity. Write it as

A= 15 (30/15=2)

So A=15 (2)

And

A+B= 10 (30/10=3)

So A+B=10 (3)

The values 2 and 3 are A and A+B’s one day work.

Step 3. Now A=2 and A+B=3 (equating to values given in brackets)

We get B=1

So B will finish that work in 30/1=30 days Ans. (because B=1)

If it is asked that in how many days, will A finish that work, then

30/2=15 (because A=2)

When solving in paper, don’t write as long as I do in this post as I was doing it just to explain the trick completely. If you practice these questions with this trick then you can easily solve them in 10 seconds.

Stay in touch for more time and work problems and other types of tricks.