Aptitude Day 177

Answers of Day 176: 

1.       20.

2.       4200.

Problems on Average:

1. The average weight of 10 persons increases by 3 kg when a new person comes in place of one of them weighing 40 kg. What might be the weight of the new person?

Solution:

                Increased sum = 3*10 = 30.

                Weight of the new person = 40+30 = 70 kg.

               (Note: Since the average increases by 3kg, we’re adding 30 to 40)

2.The average weight of 3 men A, B and C is 50 kg. Another man D joins the group and the average now becomes 60 kg. If another man E, whose weight is 5 more than that of D, replaces A, then the average weight of B, C, D and E becomes 58 kg. The weight of A is:

Solution:

                 A+ B+ C = 50(3) = 150

                 A+ B+ C+ D = 60(4) = 240

                 B+ C+ D+ E = 58(4) = 232

                 E = D+5

                (A+ B+ C+ D)- (A+ B+ C) = D = 240-150 = 90.

                E = 90+5 = 95.

                (A+ B+ C+ D)-(B+ C+ D+ E) = A-E = 240-232 = 8.

                A = E+8 = 95+8 = 103.