Question

If one score oranges cost Rs. 45, how many oranges can be bought for Rs. 72 ? (1 score = 20).

Answer 1

The cost of the oranges is directly proportional to the number of oranges bought.

A score of oranges, means $20$ oranges.

Let $a$ be the number of oranges bought for $Rs72$.
So, $=>45:72=20:a$

Applying the rule, product of extremes $=$ product of means

$45\times a=72\times 20$

$a=\frac{72\times 20}{45}$
$a=32$

Hence, $32$ oranges can be bought with $Rs72$.