Question

The sum of three consecutive multiples of 7 is 357.find the smallest multiple.

Answer 1

112, 119 and 126.

Explanation:

Let the consecutive multiples of 7 be 7n, 7(n+1) and 7(n+2) where n is an integer, then:-

7n + 7n + 7 + 7n + 14 = 357

21n + 21 = 357

21(n + 1) = 357

n = (357/21) - 1

n = 17 + 1 = 16.

So the numbers are 7*16 = 112, 7*17 = 119 and 7*18 = 126.