A, B, and C all weigh 45 kg on average. If A and B's average weights are 40 kg and B and C's are 43 kg, then B's weight is:
A. 17 KG
B. 20 KG
C. 26 KG
D. 31 KG
Answer:D
A, B, and C all weigh 45 kg on average. If A and B's average weights are 40 kg and B and C's are 43 kg, then B's weight is:
A. 17 KG B. 20 KG C. 26 KG D. 31 KG
Explanation: Let's use the letters A, B, and C to symbolise their respective weights. Then there's:(45 x 3) = 135 = A + B + C... (i),(40 x 2) = 80 = A Plus B... (ii),(43 x 2) = 86 = B + C... (iii),We get A + 2B + C = 166 by adding (ii) and (iii) (iv),We get B = 31 by subtracting I from (iv).B's weight is 31 kg.