The average weight of R, P and K is 40 kg. If the average weight of P and K is 45 kg and average weight of R and K is 35 kg, then what is the weight of K?
Answer & explanation
Correct answer: option 1
Let's assume weight of R, P & K are also denoted by same letters
R + P + K = 40 x 3 =120 -------------- 1
P + K = 45 x 2 = 90 ---------------2
R + K = 35 x 2 = 70 ---------------3
Add. equation 2 & 3
R + P + 2K = 160 ---------------4
From 1 and 4
(160 - 2K) + K = 120
K = 40