'n' litres of oil was poured into a tank and it was still e% empty. How much oil must be poured into the tank in order to fill it to the brim?
The correct option is D ne100−e
Given n litres of oil poured into the tank and
the amount space still empty is e%
Let capacity of bank =C litres then
amount of space still empty =e% of C
=e100+C
Since, capacity of tank=filled space+empty space.
⇒C=n+e100×C
⇒C−eC100=n
⇒C(1−e100)=n
∴C=n×100100−e
Suppose x L is to be poured to fill the tank completely.
So, x= total capacity of tank−amount of oil filled.
⇒x=C−n
=100n100−e−n
=100n−100n+ne100−e
∴x=ne100−e