Aptitude - Time and Work - Discussion

Anyone explain the correct answer.

Taniya can do 25% more than Sakshi
i.e., Taniya = 100%+25% = 125%of Sakshi
Sakshi 1 day of work is 1/20 then 125% of 1/20
i.e., 1.25*(1/20) = 1/16 in one day for Taniya
So, the work will be completed in 16 days.

As Sakshi can do 1/20 per day, Tanya can do 25% more per day than Sakshi.
So, [(1/20)+(1/20)*(25/100)].

i.e. 5/80 i.e 1/16 i.e 16 days.

25% efficient means Tanya takes 15 days.
Both 1 day work=1/20+1/15=7/60.
Tanya work=7/60-1/20=1/15.
Why can't the answer be 15?

@Ashan Naveed.

Consider 100 unit by Sakshi
Tanya 125 unit. Y can't we consider Sakshi by 125 days. Tanya in 100 days. Mainly unitary method how can we solve.

Can anyone please compare it with the 17th question?

@All.

The sentence 'Tanya is 25% more efficient than Sakshi' means Tanya will take 25% less days than Sakshi and not that Sakshi will take 25% more days than Tanya. The answer given assumes the later part which is not correct. Percents work differently for the increase and decrease.

For example, 25% more than 100 is 125. But 25% less than 125 is not a hundred.

The answer would be 16 if the question had been stated as Sakshi is 25% less efficient than Tanya.

Here (125% of 1/20)=1/16 that means in 16 days.

A certain number of men do a piece of work in 10 days, if there are 10 men less, it will take 10 days more to finish the work. How many men were there originally. Can anyone solve this to find a solution?

@All.

Tania is 25% more efficient then Sakshi so we can do it like,
Tania=125 units/day, Sakhi = 100 units/day.
As Sakhi done it in 20 days so we can find complete work done,
Total work= 20 * 100 = 2000.

We also have Tania unit work so we will divide total work with Tania unit work,
Tania work= 2000/125 = 16 answer.