Aptitude - Time and Work - Discussion

How come Remaining work 1-7/15 (note:- why come 1 value )

Thank you sundar nice explanation

@Swetha why mutiply with (A*TOTAL CAPACITY)?

@Rashmi, @Satish : 1/15 + 1/20 Now to make the denominator value equal take LCM i.e. ,
= (1*20) / (15*20) + (1*15) / (15*20) Now simplify these,
i.e. , multiply the values i.e. ,
= (20/300) + (15/300).
Now, both the denominator are equal, so you can add the numerator values i.e. , = (20+15) /300 = 35/300,
Now simplifying this i.e. , cancelling both numerator and denominator by 5 (a common value which both will get cancel) ,
We get 7/60. Hope this will help you to understand the problem.

1/15+1/20= 7/60 How ? Please explain me clearly.

How did you get 7/60 please answer in simple method and tell how got 7.

How did 7/20 come?

Good explanation anshu.

"A" can can do a work in 15 days therefore he did 1/15 of the work in a day.
"B" can do the same work in 20 days therefore he did 1/20 of the work in a day.

Therefore.

[1/15 + 1/20]4 = [4/60 + 3/60]4.

[7/60]4 = 7/15 of the work done.

The total work left = 1 - 7/15 = 15 - 7/ 15 = 8/15.

Hi Manoj,

You need to simplify big number 35/300 in to small number for further calculation.

So, you need to divide one common number of both numerator and denominator.

You couldn't select 2, 3 and 4 as a dividing number. But you can use 5 as a common divider.

If you divide 5 in both numerator and denominator, you will get 7/60.

I hope your doubt clarified.