Average weight of three friends A, B and C is 53 kg. Another person D joins the group and now the average is 49 kg. If another person E whose weight is 8 kg more than D, joins the group replacing A, then average weight of B, C, D and E becomes 51 kg. What is the weight of A (in kg)?

Average weight of three friends A, B and C is 53 kg. Another person D joins the group and now the average is 49 kg. If another person E whose weight is 8 kg more than D, joins the group replacing A, then average weight of B, C, D and E becomes 51 kg. What is the weight of A (in kg)? Correct Answer 37 kg

Formula Used

Average = Total/number of terms

Calculation

A + B + C = 53 × 3 = 159 kg

A + B + C + D = 49 × 4 = 196 kg      ---- (I)

⇒ D = 196 – 159 = 37 kg

So, E = D + 8

E = 37 + 8 = 45 kg

Now,

B + C + D + E = 51 × 4 = 204 kg      ---- (II)

From equation (I) and (II),

E – A = 204 – 196 = 8 kg

⇒ 45 – A = 8

⇒ A = 37 kg