The best way to find out what 7 sweets cost, firstly, you should find out what one sweet would cost. You have 5 sweets, with a total cost of 30p. You should divide 30 by 5, giving you 6p per sweet. To get the cost of 7 sweets, you have to multiply 6p by 7, giving you 42p.
Therefore, the cost of 7 sweets is 42p.
Hope this helps :)
