Percentage for selling price = 100%

Percentage received = 100% - Commission%

Percentage received = 100% - 9%

Percentage received = 91%

Amount received = GH₵ 236,600

If 91% = GH₵ 236,600

100% = $\frac{\mathrm{GH₵\; 236,600\; x\; 100\%}}{\mathrm{91\%}}$ = GH₵ 260,000

∴ Selling price = GH₵ 260,000.00

Discount % = $\frac{\mathrm{Discount}}{\mathrm{Actual\; Price}}$ x 100%

Discount = Actual Price - Selling Price

Actual price for the 5 tins = GH₵ 15.00 x 5
Actual price for the 5 tins = GH₵ 75.00

Discount = GH₵ 75.00 - GH₵ 66.00
Discount = GH₵ 9.00

Discount % = $\frac{\mathrm{GH₵\; 9.00}}{\mathrm{GH₵\; 75.00}}$ x 100%

Discount % = 12%

100 kobo = 1 naira

38 kobo = $\frac{38}{100}$ naira = ₦ 0.38

0.38 x cost of engine = import duty

cost of engine = $\frac{\mathrm{import\; duty}}{0.38}$

cost of engine = $\frac{\mathrm{₦\; 22,800.00}}{\mathrm{₦\; 0.38}}$ = ₦ 60,000

Selling Price = Cost Price + Profit

Selling Price of each = ₦ (x + y)

For the 10 tins, selling price = 10 x ₦ (x + y)

Amount received for the 10 tins = ₦ 10(x + y)

100% represents the cost price.

Selling Price % = Cost Price % + Profit %

Profit % = 15%

Selling Price % = 100% + 15%

Selling Price % = 115%

Selling Price = ₦6,900

If 115% = ₦6,900

100% = $\frac{\mathrm{₦6900\; x\; 100\%}}{\mathrm{115\%}}$ = ₦6,000

Cost price = ₦6,000

Profit = Selling Price - Cost Price

Profit when sold at ₦6600 = ₦6600 - ₦6,000

Profit when sold at ₦6600 = ₦600

If ₦6,000 = 100%

₦600 = $\frac{\mathrm{₦600\; x\; 100\%}}{\mathrm{₦6000}}$ = 10%