Question

4) The average of three numbers is 59. When six more
numbers are included the average becomes one-third of
the previous average, what is difference between the
averages of the two set of numbers?
(a) 19.4
(b) 19.3
(c) 19.5
(d) 9.7
(e) 20.17​

Answer 1

Explanation:

a+b+c= (3*59)

Let six new numbers be y then

a+b+c +y= (59 +1/3) * 9

On solving we get difference as 20.17