Question

if a family of 7 persons can live on 840 rupees for 36 days,how long can a family if 9 persons live on 810 rupees?

Answer 1

7 persons = 840 rupees = 36 days
9 persons = 810 rupees = ? days

810 / 840 = 36 / x
$\frac{810}{840} = \frac{36}{x} \\ 810x = 840 \times 36 \\ x = \frac{840 \times 36}{810} \\ x = 37.3333.....$
family of 9 persons live on a 10 rupees for 37.333 days