If the sum of three consecutive multiples of 6 is 126, then the third multiple is :
48
If x is a multiple of 6, then next two multiples are x + 6 and x + 12
So three consecutive multiples of 6 are x, x + 6, x + 12
x + (x + 6) + (x + 12) = 126
3x + 18 = 126
x = 126−183 = 1083 = 36
So, first multiple is 36
Second multiple is 36 + 6 = 42
Third multiple is 36 + 12 = 48.