Question

The average weight of Mandar, Ketan and Tushar is 45 kg. If the average weight of Mandar and Ketan be 43 kg and that of Ketan and Tushar be 48 kg, then the weight of Ketan (in kg) is:

• A. 62
• B. 47
• C. 67
• D. 57

Answer 1

Answer:

B. 47

Let the weights be:

• Mandar = (M)

• Ketan = (K)

• Tushar = (T)

Average of Mandar, Ketan, Tushar = 45
$\frac{M + K + T}{3} = 45 \Rightarrow M + K + T = 135$

Average of Mandar and Ketan = 43
$\frac{M + K}{2} = 43 \Rightarrow M + K = 86$

Average of Ketan and Tushar = 48
$\frac{K + T}{2} = 48 \Rightarrow K + T = 96$

Find Ketan’s weight

Add the last two equations:
$(M + K) + (K + T) = 86 + 96 = 182$

But (M + K + T = 135), so:
$182 - (M + K + T) = K$
$K = 182 - 135 = 47$

Weight of Ketan = 47 kg