Question

The sum of three consecutive even numbers is 78. What is the first number? a. 24 b. 26 c. 28 d. 30

Answer 1

a. 24

Explanation:

`n,\ n+2,\ n+4-\text{first three consecutive even numbers}\\\\\text{The equation:}\\\\n+(n+2)+(n+4)=78\\\\3n+6=78\qquad\text{subtract 6 from both sides}\\\\3n=72\qquad\text{divide both sides by 3}\\\\n=24`