Question

The average of a & b is 15 ; the average of b & c is 12 and the average of a &c is 13. What is the value of b ?

Answer 1

Answer:

b = 14

Step-by-step explanation:

Given that,

Average of a and b is 15.

=> (a+b)/2 = 15

=> a + b = 15 × 2

=> a + b = 30 .....(1)

Average of b and c is 12.

=> (b+c)/2 = 12

=> b + c = 12 × 2

=> b + c = 24 .......(2)

Average of a and c is 13.

=> (a+c)/2 = 13

=> a + c = 13 × 2

=> a + c = 26 .......(3)

To find the value of b.

subtracting eqn (3) from (1), we get,

=> b - c = 30 - 26

=> b - c = 4 ......(4)

Now, adding eqn (2) and (4), we get,

=> b + b = 24 + 4

=> 2b = 28

=> b = 28/2

=> b = 14

Hence, required value of b = 14.