Question

The average of four numbers is 21 ,of the average of three of them is twice than the fourth number then find the fourth number

Answer 1

Answer:

18

Step-by-step explanation:

Proof:

a,b,c,d are 4 numbers. d is the fourth in the series.

Given

(a+b+c+d)/4=24

(a+b+c+d)=24*4

(a+b+c+d)=96 (i)

Given

(a+b+c)/3=26

(a+b+c)=26*3

(a+b+c)=78 (ii)

Now,

(ii) -> (i)

(78 + d) = 96

d = 96 - 78

d=18

Since d is the fourth number in the series, the fourth number is 18.