Explanation:

Let’s break down how these numbers are related.

- First pair: 21 : 112

Look for a pattern. If you do 21 × 5 + 7, you get 105 + 7 = 112.

- Let’s see if the next pair fits that same pattern: 36 : ?

Try 36 × 5 + 7 = 180 + 7 = 187. That’s not one of the options.

- Try a different relationship. Check for cubes:

21 × 21 + 21 = 441 + 21 = 462. Nope.

Try 21 × 5 + 7 = 112. That worked before. What if we do × 5 + 7 for all?

- Try for the last pair: 51 : 272

51 × 5 + 7 = 255 + 7 = 262. No.

But 51 × 5 + 17 = 255 + 17 = 272. Now that works!

So the pattern might be “multiply by 5, then add an increasing odd number”—possibly +7, +17, etc.

Now, try to see which number fits for the middle pair, 36 : ?

- Option 1: 192

36 × 5 + 12 = 180 + 12 = 192

- Let’s confirm with the pattern: first +7, second +12, third +17

So,

21 : 112 (21 × 5 + 7 = 112)

36 : 192 (36 × 5 + 12 = 192)

51 : 272 (51 × 5 + 17 = 272)

Answer: Option 1 - 192