Question

If x+1, 3x and 4x+2 are in A.P., find the value of x.

Answer 1

We know that if three numbers , say a , b , c are in A.P then b = ( a + c )/2

So x + 1 , 3x , 4x + 2 are in A.P

3x = (x +1 + 4x + 2)/2

6x = 5x + 3

x = 3

Hence the three numbers are 4, 9 , 14.