Question

a circle divided into six sectors with numbers 8, 13, 18, 24, 39 and a question mark (?) in each sector. the circle is shown on a computer screen with an orange background and a white desk surface.

Explanation:

Step1: Identify opposite pairs

Opposite numbers: 8&24, 13&39, ?&18

Step2: Find the ratio

$24÷8=3$, $39÷13=3$

Step3: Calculate the unknown

$18÷3=6$

Answer:

6