Answer:
If a customer paid 100$ they used 750 international call minutes.
Explanation:
If you are already paying 25 dollars that means you are paying 75 extra for international call minutes. With one minute being $0.10 that means 10 minutes is a dollar. From there you can multiply your dollar for 10 minutes by 75 which now adds 75 dollars which means we used 750 minutes. (This is my first time answering good luck :)