Question

a man buys two pens at ripped 20 each . he sells one at a gain of 5 % and other at a loss of 5% find his gain or loss percentage​

Answer 1

Answer:

$cp \: of \: both \: the \: pens = 20rs \\ profit \: on \: first \: pen = 5\% \\ sp \: on \: first \: pen \: = ( \frac{100 + p}{100} ) \times cp \\ = ( \frac{100 + 5}{100} ) \times 20 \\ = \frac{105}{100} \times 20 \\ = 21rs \\ \: so \: sp \: of \: first \: pen \: is \: rs 21 \\ loss \: on \: second \: pen \: = 5\% \\ so \: sp = ( \frac{100 - l}{100} ) \times cp \\ = ( \frac{100 - 5}{100} ) \times 20 \\ = \frac{95}{100} \times 20 \\ = 19rs \\ so \: sp \: of \: second \: pen \: = 19rs \\ cp \: of \: whole \: transaction = (20 + 20) = 40 \\ sp \: on \: whole \: transaction = (21 + 19) = 40 \\ as \: both \: cp \: and \: sp \: are \: same \\ so \: there \: will \: be \: niether \: profit \\ \: nor \: loss$