Question

A person buy some pencil 5 for a rupee and sell them at 3 for a rupee find his gain percent

Answer 1

cp of 5 pencil=rs 1
cp of 1 pencil=rs 1/5
sp of 3 pencil= rs 1
sp of 1 pencil=rs 1/3
$profit = sp - cp \\ p = \frac{1}{3} - \frac{1}{5} \\ p = \frac{2}{15} \\ p\% = \frac{p \times 100}{cp} \\ p\% = \frac{ \frac{2}{15} \times 100}{ \frac{1}{5} } = 66.66$