Question

a fruit seller buys 100kg apple at the rate of rs 20 per /kg . He sold 40 kg at a loss of 7%.At what price should we sell the remaining apple to make a profit of 15% on the whole transaction ??

Answer 1

cost to buy = 100(20) = rs 2000
a profit of 15% is rs 300
so his return must be rs 2300

selling price of remaining apples --- rs x/kg

so...
.93(20)(40) + x(60) = 2300
60x = 2300 - 744
x = 25.93

check:
a loss of 7% ---> sold at .93(20) or 18.6

so 40(18.6) + 60(25.93) = 2299.8 , close enough