The product 620 × 28a is divisible by 15. The value of a is:Options 1 2 3 4

The product 620 × 28a is divisible by 15 means that the product is a multiple of 15.

The prime factors of 15 are 3 and 5.

We know that 620 is a multiple of 5, so for the product to be a multiple of 15, 28a must be a multiple of 3.

The rule for divisibility by 3 is that the sum of the digits of the number must be divisible by 3.

In 28a, 2 + 8 = 10.

So, we need to find a value of a such that 10 + a is divisible by 3.

The options are 1, 2, 3, and 4.

If a = 1, then 10 + 1 = 11, which is not divisible by 3.

If a = 2, then 10 + 2 = 12, which is divisible by 3.

So, the value of a is 2.