If the total is 0.45 and one part is 0.25, what is the other part?

To find the other part when you know the total and one part, you can simply subtract the known part from the total. In this case, the total is 0.45, and one part is 0.25.

By performing the subtraction:

0.45 (total) - 0.25 (one part) = 0.20.

This calculation shows that the other part, which completes the total, is 0.20. Therefore, the calculation confirms the correct choice as being 0.20. Each option represents a different possible value that could be the other part, but only 0.20, when calculated with the total, matches the provided condition that the sum of the known part and the other part equals the total.