Question

The average weight of 3 person's increases by 3 kg when a new person comes in place of one of them weighing 30 kg. What might be the weight of the new person?34 kg36 kg39 kg40 kg

Answer 1

Answer:

39 kg

Step-by-step explanation:

Let the average weight of 3 people be avg.

So, avg= total weight of 3 people/3------equation 1

Let the weight of the new person be x kg.

Replacing it from the weight of the removed person, total weight of 3 people will be = total weight of 3 people -30 + x-----equation 2

But the average increases by 3 kg.

So, new average= avg + 3=(total weight of 3 people -30 +x)/3(from -----equation 2)-------equation 3

putting equation 1 in 3;

=>total weight of 3 people/3 + 3=(total weight of 3 people -30 +x)/3

=>total weight of 3 people+ 9 =total weight of 3 people-30 +x

=>x=39 kg

Thus, the weight of the new man is 39 kg.