Answer:
20%
Explanation:
The profit made on each calculator is the selling price minus the cost price, which is:
£6 - £5 = £1
The percentage profit is the profit as a percentage of the cost price, which is:
(Profit / Cost Price) x 100%
Substituting the values we have:
(1 / 5) x 100% = 20%
Therefore, the percentage profit made by the school on each calculator is 20%.