Question

1. The averages of 10 different values is 485. If three
values are increased by 20 each and one value is
decreased by 10, what is the new average of the 10
values?
(a) 460 (b) 480
(c) 490 (d) 500
- 1​

Answer 1

Resposta:

In this question,

Average of 20 values = A = 18

Sum of all the 20 values= S = average * 20

=A*20

=18*20

=360

If 3 is substracted from each of the 20 values, then total value substracted = 3*20=60

Now new Total Sum = S1=S - 60

=360–60

=300

New Average = (New Sum) / 20

=300/20=15