The average weight of A, B and C is 60 kg. If the average weight of B and C is 50 kg and that of A and B is 52 kg, then what is the weight of B?

24 kg

We have,

The average weight of A, B and C = 60 kg

So, the total weight of A, B and C = 60 × 3 = 180 kg

The average weight of B and C = 50 kg

So, the total weight of B and C = 50 × 2 = 100 kg

The average weight of A and B = 52 kg

So, the total weight of A and B = 52 × 2 = 104 kg

Now, the weight of A = 180 - 100 = 80 kg

The weight of C = 180 - 104 = 76 kg

So, the weight of B = 180 - 80 - 76 =  24 kg