The average weight of 4 men, A, B, C and D is 67 kg. The 5th man E is included and the average weight decreses by 2 kg. A is replaced by F. The weight of F is 4 kg more then E . Average weight decreases because of the replacement of A and now the average weight is 64 kg. Find the weight of A.

Sum of the weight of A, B, C and D = 67 x 4 = 268 kg
and average weight of A, B , C , D and E = 67 - 2 = 65kg
∴ Sum of the weight of A, B, C, D and E = 65 x 5 = 325 kg
∴ Weight of E = 325 - 268 = 57 kg
∴ Weight of F = 57 + 4 = 61 kg
Now, average weight of F, B, C, D and E = 64 kg
∴ Sum of the weight of F, B, C, D and E = 64 x 5 = 320 Kg
∴ Sum of the weights of B, C and D = 320 - 57 - 61 = 202 kg
∴ Weight of A = 268 - 202 = 66 kg