Could you multiply a number by 2 and get a product of 15

No you can't multiplying by two I 's basically adding up two numbers till you get it

Yes, 7.5 can be multiplied by 2 to get 15.

Provided that number / 2 = / = imaginary number, then you can always multiply by two to reach said number.

Example 1)

8

8 / 2 = 4

4 * 2 = 8

Example 2)

4

4 / 2 = 2

2 * 2 = 4

Example 3)

15 / 2 = 7.5

7.5 * 2 = 15

Hopefully I haven't misinterpreted your question.