The average weight of 3 men, A, B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man E whose weight is 3 kg more than that of D, replaces A then the average weight of B, C, D and E becomes 79 kg. What is the weight of A ?

A. 70 kg

B. 72 kg

C. 75 kg

D. 80 kg

Answer: Option C

Solution(By Examveda Team)

A + B + C = 84 × 3 = 252.....(i)
A + B + C + D = 80 × 4 = 320.....(ii)
On solving equation (i) and (ii)
D = 320 - 252
D = 68
E's weight = 68 + 3 = 71
B + C + D + E = 79 × 4 = 316
B + C + D + 71 = 316
B + C + D = 316 - 71 = 245
Now, from equation (ii)
(A + B + C + D) - (B + C + D)
A = 320 - 245
∴ A = 75 kg