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:

Correct option is B

Given:

The average weight of Mandar, Ketan, and Tushar is 45 kg.

The average weight of Mandar and Ketan is 43 kg.

The average weight of Ketan and Tushar is 48 kg.

Formula Used:
Average weight = $$\frac{\text{total weight}}{\text{number of people}}$$​​

Solution:

Let M = Mandar's weight, K = Ketan's weight, and T = Tushar's weight

The average weight of three people :

$$\frac{M + K + T}{3}$$​ = 45

M + K + T = $$45 \times 3$$​ = 135 …………(1)

The average weight of Mandar and Ketan:

$$\frac{M + K}{2}$$​ = 43

M + K = $$43 \times 2$$​ = 86 ……………….(2)

The average weight of Ketan and Tushar:

$$\frac{K + T}{2}$$​ = 48

K + T = $$48 \times 2$$​ = 96 …………..(3)

Adding, equation (2), and (3):

M + 2K + T = 182 ……(4)

Now, Subtracting eq(3) from eq.(4)

(M + 2K + T) – (M + K + T) = 182 – 135

K = 47

Thus, the weight of the Ketan is 47 year.