The average weight of a group of 10 girls is 48 kilograms. If 2 girls R and S, replace by P and Q then the new average weight is 46 kg. The weight of P is equal to the weight of Q and the weight of R is equal to the weight of S, another girl T joins the group and the new average weight of the group becomes 46 kg. The weight of T is equal to the weight of P. What is the weight (in kg) of R?
The average weight of a group of 10 girls is 48 kilograms. If 2 girls R and S, replace by P and Q then the new average weight is 46 kg. The weight of P is equal to the weight of Q and the weight of R is equal to the weight of S, another girl T joins the group and the new average weight of the group becomes 46 kg. The weight of T is equal to the weight of P. What is the weight (in kg) of R? Correct Answer 56
Given:
Average weight of 10 girls = 48 kg
Formula:
Average weight = Sum of weight/Total members
Calculation:
Total weight of 10 girls = 48 × 10 = 480 kg
After R and S gone then P and Q join the group then the average weight = 46 kg
Now, total weight of 10 girls = 46 × 10 = 460 kg
Weight, R = S and P = Q
According to the question,
480 – 2R + 2P = 460
⇒ R – P = 10 ----(i)
After entry of T in the group, the average weight of the group remains unaffected.
⇒ Weight of T = 46 kg
Weight, T = P = 46 kg ----(ii)
From (i) and (ii), we get
R – 46 = 10
∴ Weight of R = 56 kg