Question

$25people$have enough food for $15days$ How long would the food last if $5people$leave the house?

Answer 1

According to the question,

$25people$have enough food $=$ $15days$

$1people$have enough food $=$ $\frac{15}{25}days$

$20people$have enough food $=$ $\frac{15\times 20}{25}days$ ( As $5people$leave the house. So the remaining people are $25-5=20people$)

so, $20people$have enough food $=$ $\frac{300}{25}days$( Simplify $\frac{300}{25}$by dividing by a common factor $25$in numerator and denominator separately )

$20people$have enough food $=$ $12days$

Hence, if $5people$leave the house, the food will last for $12days$