First you want to find out how many coins there are in bag A. So how many 20p coins do you need to make £7.20? This is the same as 720p. 720 divided by 20 is the same as 72 divided by 2 which is 36. So there are 36 coins in bag A. We know that the number of coins in bag B is three quarters of the number of coins in bag A so we have to find 3/4 of 36. This can be found by dividing 36 by 4 and multiplying by 3. This gives you 27. Telling you that there are 27 5p coins in bag B. So the value of bag B is 27 multiplied by 5p which is 135p, which equals £1.35.