Aptitude - Time and Work - Discussion

Tanya's one day work =(1/20 + 25% of 1/20) = 1/20+1/80 = 1/16 once explain the equation.

20*0.25=5
subtract 5 from 20
20-5=15Ans

I also get the answer 15
I did not understand how the answer is 16.

Thanks Kamlesh !!!

I too get the answer as 15 days. Since 25% of 20 is 5 we have to subtract like 20-5=15 rite? but how the answer is 16?

25% efficient(so one takes 100 days means second person takes 75days[just 75%of 100])

here one takes 20 days
so other takes 20*(75/100)=15 days

5 : 4 :: 20 : x

Can you explain the meaning of the above line?

Thanks sundar that solves so many other related problems.

Can't we take time taken by tanya and sakshi as 75:100.

@Sujith and @Sandeep

You are wrong.

The given ratio is about "TIME TAKEN" not the ratio of work done.

If Tanya is more efficient (25%) than Sakshi - means Tanya will take less time than Sakshi to complete the work.

We can say the same thing in another way, i.e., Sakshi is 25% INEFFICIENT than Tanya. So, if Tanya takes 100 hours to complete a task then Sakshi will take 125 hours (25% extra than Tanya) to complete the same task.

So, time taken by
Tanya = 100 hours ,
Sakshi = 125 hours.

Therefore, Ratio of times taken by Sakshi and Tanya = 125 : 100 = 5 : 4.

This is what the first line in the given explanation.

Hope this will help you. Have a nice day!

Tanya is 25% more efficient than Sakshi. Then ratio should be 3:4 rite ?.