Question

The sum of three consecutive odd numbers is $20$ more than the first number. What is the middle number?

Accepted Answer

D. Let the consecutive odd numbers be $x-2, x, x+2$. Sum $= (x-2) + x + (x+2) = 3x$. Given: $3x = (x-2) + 20 \implies 3x = x + 18 \implies 2x = 18 \implies x = 9$. The middle number is $9$.

Sum of consecutive odd numbers

Explanation

Practise this under exam conditions