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
Show Answer
Answer-C
Solution-
Solution(By Apex Team)
$\begin{array}{l}\text{A + B + C = 84 × 3 = 252…..(i)}\\
\text{A + B + C + D = 80 × 4 = 320…..(ii)}\\
\text{On solving equation (i) and (ii)}\\
\text{D = 320 – 252}\\
\text{D = 68}\\
\text{E’s weight = 68 + 3 = 71}\\
\text{B + C + D + E = 79 × 4 = 316}\\
\text{B + C + D + 71 = 316}\\
\text{B + C + D = 316 – 71 = 245}\\
\text{Now, from equation (ii)}\\
\text{(A + B + C + D) – (B + C + D)}\\
\text{A = 320 – 245}\\
\text{∴ A = 75 kg}\end{array}$
