Answer:
Step-by-step explanation:
You would never buy a 10-pack, because two 5-packs cost less.
To buy 3 bars you need a single bar and a pair of single bars for £0.82 + £0.82+ £0.41 = £2.05
To buy 30 bars you need 3 pairs of 5-bar packs = 3×£5.75 = £17.25
To buy the remaining 5 bars you need one 5-bar pack = £3
cost = £2.05 + £17.25 + £3 = £22.30
