The product of a pair of 2-digit positive integers is 630. How many such pairs arethere?(A) 2 (B) 3 (C) 4 (D) 5 (E) 6

To solve this problem, we need to find all the pairs of two-digit numbers that multiply to give 630.

Step 1: Find the factors of 630.

The factors of 630 are: 1, 2, 3, 5, 6, 7, 9, 10, 14, 15, 18, 21, 30, 35, 42, 45, 63, 70, 90, 105, 126, 210, 315, and 630.

Step 2: Identify the pairs of factors that are both two-digit numbers.

From the list of factors, the pairs that are both two-digit numbers are: (15, 42), (18, 35), and (21, 30).

So, there are 3 pairs of two-digit numbers that multiply to give 630.

Therefore, the answer is (B) 3.