Answer:
N688.97
Explanation:
Percentage profit = [Selling price - Cost price/Cost price ]× 100
Percentage profit = 15%
Cost price = x = ??
Selling price = N690
Hence:
15% = (690 - x /x)× 100
0.15 = 100(690 - x)/x
Cross Multiply
0.15x = 69000 - 100x
Collect like terms
0.15x + 100x = 69000
100.15x = 69000
x = 69000/100.15
x = 688.96655017.
Approximately = 688.97
Therefore, the Cost price of the drone = x = N688.97