Question

A shopkeeper sold two radio at Rs 700 each. On one he gains 12% and on the other he less 20%. Find
the loss or gain percent in the whole transaction.​

Answer 1

$\textrm{ ⚝GIVEN:-}$

$\tt f1st \: radio - \\ \tt s.p = rs.700 \\ \tt gain = 12\%$

$\tt 2nd \: radio - \\ \tt s.p = rs.700 \\ \tt gain = 20\%$

$⍣ \tt FIND:-$

Total gain or loss in whole transaction.

$\tt ❂SOLUTION:-$

$\tt selling \: price = \frac{100}{(100 + gain)} \times c.p. \\ \tt = \frac{100}{100 + 12} \times 700 \\ \tt = \frac{ \cancel{ 70000}}{ \cancel{ 112}} = rs.625$

$\tt selling\: price = \frac{100}{(100 - loss)} \times c.p. \\ \tt = \frac{100}{100 - 20} \times 700 = \frac{100}{8 \cancel0} \times 70 \cancel 0 \\ \tt = \frac{ \cancel{ 7000}}{ \cancel8} = rs.875$

$\tt \therefore total \: selling\: price \: is = rs.625 + 875 \\ \tt = rs.1500$

$\tt total \: cost \: price \: is = rs.700 \times 2 \\ \tt = rs.1400$

$\tt Thus, \: cost \: price \: is \: greater \: than \: \\ \tt selling \: price$

$\tt hence, \: there \: is \: a \: loss \: of \: rs.100$

$\tt L\% = \frac{ L}{cost\:price}\times100$

$\tt = \frac{100}{1400}\times100$

$\tt=7.142 \%$