Explanation:

Let's analyze the pattern for each pair:

- 52 : 221

- 20 : ?

- 64 : 272

Look for a relationship (possibly involving multiplication, addition, or another operation):

- 52 × 4 + 13 = 208 + 13 = 221

- So, the rule seems to be: Number × 4 + 13

Check this rule for the other pairs:

- For 20: 20 × 4 + 13 = 80 + 13 = 93

- So, the answer in place of ? should be 93, but it's not given in the options.

Now, check the relationship for 64 : 272:

- 64 × 4 + 16 = 256 + 16 = 272

- So here, the formula might be Number × 4 + (number of the pair, like 13 for first, 16 for third)

Let's check option values for 20 with similar logic:

- Options: 85, 84, 255, 170

- Try 20 × 4 = 80, none fit by simple addition

- Pattern not matching, let's check if it's ×4 + 5: 20 × 4 + 5 = 85 (Option 1)

But, let's verify this pattern with others:

- 52 × 4 + 13 = 221 ?

- 20 × 4 + 5 = 85 (Option 1)

- 64 × 4 + 16 = 272 ?

So, for the middle pair, additional number is 5 (like 13, 5, and 16 for each pair). The formula is:

First number × 4 + specific number (13, 5, 16)

Correct Option:

- Option 1: 85

Summary:

- The rule for each pair is Number × 4 + a specific value.

- For 52, it’s ×4 + 13 = 221

- For 20, it’s ×4 + 5 = 85

- For 64, it’s ×4 + 16 = 272

- Only option 1 (85) fits for 20; others do not fit the pattern.