Answer:
£18.50-5%= £17.57
£149.49-5%= £142.01
now you have to sum the original price of the lamp and the original price of the lawnmower
£18.50+£149.49= £167.99
now you have to sum the price with the riduction
£17.57+£142.01= £159.58
to see how much he saves, you have to make the difference between the original total and the new total
£167.99-£159.58=£8.41