The average weight of 10 men is decreased by 6 kg when one of them weighing 300 kg is replaced by another person. This new person is again…

Let the average weight of ten persons be X kg and the weights of the persons, entered the group the first time and second time be (P) and (P-60) kg respectively,

Now,

Average = sum of elements/number of element

Now, according to the question,

$({{10X + P - 300} \over {10}} = X - 6,)$

Solving,

P = 240 kg.

Again,

$({{10X + \left( {240 - 60} \right) - 240} \over {10}} = X - R\left( {let} \right),)$

Or, R = 6 Kg

∴ Total reduction in the average weight of the group = 6 + 6 = 12 kg.