Aptitude - Simplification - Discussion

Let us assume the tank be 100 L.
For 100L tank, it takes 25 buckets
and the new dimension of the tank is 2/5 of 100 ie 40 L. so we don t know the no of buckets to be added.

100 L = 25 BUCKETS
40 L = X.

On cross multiplying, we get 10 buckets, then how 62.5 buckets came?

Thanks guys it's really help me a lot.

Its so simple:

Just reverse the new capacity 2/5 into 5/2 then multiply it with 25.

25*5/2 = 62.5.

Let bucket size is 100 ml.
Tank size = 25*100 = 2500ml.

New bucket size = 2/5*100 = 40 ml.
Buckets required to fill 2500ml tank with 40 ml bucket = 2500/40 = 62.5.

It is told that if bucket is full(=1) 25 buckets are needed.
If bucket is 2/5 how much buckets would be needed- more or less?
Obviously answer will be more.
So in the following equation take the more value out of the two (i.e 1 & 2/5) in numerator.
1 ----- 25
2/5 --- ?
So 1 will come in numerator.
So answer will be 1*25/(2/5) = 5*25/2 = 62.5.

When you are confused what to take in numerator- ask the question-will answer be more or less.
Whatever ans. comes put that value(higher or lower in numerator).

Why do put 5/2 instead of 2/5?

Let the capacity of bucket be 10Liters
They said that it requires 25 buckets to fill the tank

Therefore capacity of tank=25*10=250

If the capacity of the bucket is reduced to to 2/5th of original capacity then New capacity of bucket=(2/5)10=4litres

No. of buckets required to fill the tank=250/4 = 62.5

Let say 1 bucket holds 5 litre of water
So now its capacity is reduced to 2/5th i.e 5*2/5= 2 Litres

25 buckets fill the tank
Therefore, Tank's capacity is 25*5=625 litres.
Currently 1 bucket's capacity is 2 litres
Therefore buckets to fill 625 litres = 625/2=62.5

@vamshi cool method and easy also thanks ....!!

Simple one:

New bucket size is 2/5 of old one

So just do =25*5/2(here 25 old buckets are needed to fill the tank)
=62.5