Question

The average of 5 consecutive numbers is 20. What will be the 8th number?
a) 28
c) 24
e) None of these
b) 39
d) 25​

Answer 1

Answer:

1.5

Let the five consecutive numbers be x, x + 1, x + 2, x + 3, x + 4

Then

5

x+x+1+x+2+x+3+x+4

=m

⇒5x+10=5m⇒5x=5(m−2)⇒x=m−2

∴ The 8 consecutive numbers are m - 2, m - 1, m, m + 1, m + 2, m + 3, m + 4, m + 5

Average of these 8 numbers =

8

m−2+m−1+m+m+1+m+2+m+3+m+4+m+5

=

8

8m+12

=m+

2

3

∴ Required difference = m+

2

m

−m=

2

3

=1.5

Answer 2

Pls find ans in attachment.