First we want to find how much an individual biscuit costs.
If 5 biscuits costs 30p, then
5 x 1 biscuit = 30p
divide both sides by 5
1 biscuit = 6p
If one biscuit costs 6p, and we want to know how much 7 biscuits cost, then:
7 x 6p =42p
7 biscuits costs 42 p
