Question

A fruit-seller had some apples. He sells 40% of them and still has 420 apples. Find the number of apples he had originally.

Answer 1

Suppose that the fruit seller initially had 100 apples.
Apples sold = 40
∴ Remaining apples = (100 − 40) = 60

Initial amount of apples if 60 of them are remaining = 100
Initial amount of apples if 1 of them is remaining = $\left(\frac{100}{60}\right)$
Initial amount of apples if 420 of them are remaining = $\left(\frac{100}{60}\times 420\right)$ = 700
Hence, the fruit seller originally had 700 apples.