Aptitude - Time and Work - Discussion

Here question starts with sakshi so we must take s=100.

Then 25% eff so T=75.
Then the ratio we get is 3:4.

Answer will be 15.
How can it be 16.

Can anyone please?

Hey,

You can understand it like this.
As we know working efficiency of sakshi is 1/20.
And working efficiency of tanya is 25% greater.

So tanya eff = 1/20*(125/100)=1/16.

Hence time 16 days.

Give a brief explain how 125:100 come?

Can you explain me chain rule please?

5:4 :: 20:x.

Sakshi is doing work with x efficiency.

Tanya is doing work with x+25% of x efficiency.

Sakshi = x work.

Tanya = x+25/100x+125x/100 = 5/4x work.

ATQ,

Sakshi is taking 20 days means x ----> 20 days.

5/4x ----> 20 x 4/5 = 16 days.

20-25%[20] = 15 days.

Hey, how come it is 16?

If Tanya takes 16 days to complete, then it means Sakshi is 25% slower than Tanya. But we have calculate Tanya's time who is 25% faster than Sakshi.

So I reckon it should be 15. Please correct me if I am wrong.

Tanya does 25% efficient work. What does this mean? This means that the work that Sakshi completes is 100% and Tanya does the same work but 125%. So see efficiency as the greater percentage of work being done by Tanya 125% is greater than 100%.

For example if a does 20 units of work in 5 hrs and b does 40 units of work in 5 hrs. Then 1 hr work of A and B is 4 and 8 respectively. What does this mean? It means that B is doing more work in same no of hrs.

Now consider it as B was doing 40 units of work in 5 hrs. So what is his time for 1 unit of work? its 5/40. i.e 1/8! and similarly for A it is 1/4. So in respect of timing who is fast or efficient? Its certainly B because 1/8 is smaller than 1/4!

Nothing to do all this just simple calculation in question it is given Tanya is 25% more efficient than Sakshi which do in 20 days.

So Tanya will do 125/100*1/20 = 4 days.

Let Sakshi completes the whole work = 100 days.

Then Tanya will complete it = 75 days.

Now, 100 = 20.

1 = 20/100 = 1/5.

75 = (1/5) *75 = 15 days.

So answer should be 15 days.