Question

A castle had enough food for 72 soldiers to last 24 days after 4 days 8 soldiers joined them how many days will the food last now?

Answer 1

no.of soldiers=72
no.of days the food lasts=24

after 4 days the food will last for 20 days for 72 soldiers
but new no. of soldiers = 80
so now,refer to the pic

$x = \frac{72 \times 20}{80}$
$x = 18$
hence,the food will last for 18 more days