math
posted by TUHITUHI .
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 ??

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 
i don't know