Question

By selling tea for $Rs67.20$ per kg, a profit of $12\%$ is made, Find quantity of tea ( in kg ) bought and sold in order to gain $Rs144.$

Answer 1

Given, Profit % by selling 1 kg of tea $=\frac{S.P-C.P.}{C.P.}\times 100=12$ %
$=>\frac{67.20-C.P.}{C.P.}\times 100=12$
$=>67.20-C.P.=0.12C.P.$
$=>1.12C.P.=67.20$
$C.P.=Rs60$
$=>Profitperkg=SP-CP=Rs67.20-Rs60=Rs7.20$
To gain $Rs144$, number of kg of tea bought and sold $=\frac{144}{7.20}=20kg$