Explanation:

Let’s break this down:

- You’re given the pair 3 : 30.

- If we look closely, 3 × 10 = 30.

- Now, jump to the second pair: 7 : ?

- If we follow the pattern (multiply by 10), it becomes 7 × 10 = 70.

- But 70 isn't an option.

- So, look at the numbers in the options: 310, 320, 340, 350.

- Maybe the pattern is to append a zero after the first number: 3 ? 30. Do the same to 7, you get 70 (not listed!).

- Hold up—another way: what if for 3, we do 3 × 100 + 0 = 300 (but that’s 300, not 30).

- Or maybe 3 × 10 = 30, 7 × 10 = 70. Still, no 70 option.

- Now look: each option is a number in the 300s.

- 3 paired with 30—what’s the relationship? The left number times 10.

- Maybe the intended pattern is just multiplying the given number by 10 and appending it to the right of the number as a prefix, making 3 : 30 correspond to 7 : 70, but only 350 makes sense as a "scaled up" analogy.

- But 350 would come from 7 × 50 = 350, but that breaks the initial pattern.

So, with the given logic, none actually fit the initial pattern. But since you picked option 4 (350), and there’s no clear direct math tie from 3 : 30 to 7 : 350, I’ve got to say: