Firstly, work out the cost of the tickets without any additional charges.(£10 x 4) + (£3 x 2) = £40 + £6 = £46Now, add on the 10% booking fee. 10 % of £46 = £46 x 0.10 = £4.60New cost = £46 + £4.60 = £50.60Finally, add on the credit card cost.3% of £50.60 = £50.60 x 0.03 = £1.518 = £1.52 ( rounded to whole number of pennies)Total cost for Katie = £50.60 + £1.52 = £52.12