A bag contains 1p, 20 and 5p coins 3/8 of the bag are 1p coins There are as many 5p coins as 1p coins in the bag. There are 640 coins in total. Work out the number of 20 coins in the bag

160 off 20p coins

Step-by-step explanation:

1 p, 20 p, 5 p coins 1 p = 3/8 of the bag 5 p = 1 p = 3/8 of the bag total coins = 640

20 p coins = 640 - 640 * (3/8+3/8) = 640 * (1 - 6/8) = 640 * 2/8 = 640 * 1/4 = 160

Step by step explanation:

20p coins = 640 - 640 * (3/8+3/8) = 640 * (-16/8) = 640 * 2/8=640*1/4=160