23 : 66 : : 72 : ______

The answer is 213.

Explanation

The logic used is:

• Multiply the first number by 3 and then subtract 3.
• For 23: 23×3−3=69−3=66
• For 72: 72×3−3=216−3=213

So, 72:213 : 213 follows the same pattern shown in the image.