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

To solve this problem, we need to determine the selling price of the remaining apples to make a profit of 15% on the whole transaction.

Let's begin by calculating the cost price (CP) of the 100kg of apples.
CP = 100kg * rs 20/kg = rs 2000

Next, we need to calculate the selling price (SP) of the 40kg apples sold at a loss of 7%.
Loss percentage = 7%
Loss amount = 7% * CP
SP = CP - Loss amount

Now, let's calculate the loss amount:
Loss amount = 7/100 * CP = 7/100 * rs 2000 = rs 140

Since the selling price is equal to the cost price minus the loss, we have:
SP = CP - Loss amount = rs 2000 - rs 140 = rs 1860

Now, let's calculate the selling price of the remaining 60kg of apples to make a profit of 15% on the whole transaction.

To calculate the selling price (SP) with a profit percentage of 15%, we use the formula:
SP = CP + Profit amount

To find the profit amount, we need to calculate the cost price (CP) of the 60kg remaining apples:
CP = rs 2000 - rs 140 (cost of apples sold) = rs 1860

Now, let's calculate the profit amount:
Profit percentage = 15%
Profit amount = 15/100 * CP

Substituting the values:
Profit amount = 15/100 * rs 1860 = rs 279

To determine the selling price (SP) of the remaining 60kg of apples:
SP = CP + Profit amount = rs 1860 + rs 279 = rs 2139

Therefore, the selling price of the remaining 60kg apples should be rs 2139 to make a profit of 15% on the whole transaction.