Let age of mother = M and age of father = F
We are given
\(\frac{M+F}{2} = 2 \times (\frac{W_1+W_2+W_3+W_4}{4})\)
\(M + F = 4 \times (\frac{W_1+W_2+W_3+W_4}{4})\)
\(M + F = W_1+W_2+W_3+W_4 \)
Average weight of the 6 family members = 128
\(\frac{M + F + W_1+W_2+W_3+W_4}{6} = 128\)
\(\frac{2 \times (W_1+W_2+W_3+W_4)}{6} = 128\)
\(W_1+W_2+W_3+W_4 = 6 \times 64\)
We need to find the average weight of the 4 children that is \(\frac{W_1+W_2+W_3+W_4}{4} = \frac{6 \times 64}{4}\)
\(= 6 \times 16\)
\(= 96\)
OA, ECarcass wrote:
The average (arithmetic mean) of the weights of a father and mother is twice the average of the weights of their 4 children. If the average weight of the 6 family members is 128 pounds, what is the average weight, in pounds, of the 4 children?
A. 64
B. 91
C. 92
D. 94
E. 96
Kudos for the right answer and explanation