Marianne has been collecting donations for her biscuit stall at the school summer fayre. there are some luxury gift tins of biscuits to be sold at £5 each, normal packets at £1 each, and minipacks of 2 biscuits at 10p each. she tells amy that she has received exactly 100 donations in total, with a collective value of £100, and that her stock of £1 packets is very low compared with the other items. amy wants to work out how many of each item marianne has. show how she can do it.

Start with the highest number of the luxury gift tins with a total cost below £100:

19 * £5 = £95

Assume lowest number of normal biscuits:

1 * £1 = £1

Calculate the number of minipacks needed to make up the difference:

40 * 10p = £4

However, the total number of items is 60. Therefore, progressively reduce the number of luxury gift tins by 1, increase the number of normal biscuits by 1, and make up the difference in minibiscuits:

18   *£5  = £90

2 * £1 = £2

80 * 20p = £8

there were a lot of them but the first one to pop up on a google search was bts