Theory question 107
Commercial Arithmetic(a) Madam Kwakyewaa imported a quantity of frozen fish costing GH¢400.00. The goods attracted an import duty of 15% of its cost. She also paid a sales tax of 10% of the total cost of the goods including the import duty and then sold the goods for GH¢660.00. Calculate her percentage profit.
(b) In a school, there are 1000 boys and a number of girls. The 48% of the total number of students that were successful in an examination was made up of 50% of the boys and 40% of the girls. Find the number of girls in the school.
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(a) Import duty = 15% of 400 = GH¢60. Sales tax = 10% of 460 = GH¢46. Total cost = GH¢506.
Profit = 660 − 506 = GH¢154. Percentage profit = 154/506 × 100% ≈ 30.4%.
(b) Let g be the number of girls: 0.5(1000) + 0.4g = 0.48(1000 + g).
500 + 0.4g = 480 + 0.48g, so 0.08g = 20 and g = 250.
Profit percentage is on the total cost, including duty and tax.