Question

If the sum of three consecutive multiples of 6 is 126, then the third multiple is ___

Answer 1

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 = $\frac{126-18}{3}$ = $\frac{108}{3}$ = 36
So, first multiple is 36
Second multiple is 36 + 6 = 42
Third multiple is 36 + 12 = 48.