I think the answer is yes you can because they are both different things.
What I mean by that is that the United Stated as .151% of its people with hearing problems, and .093% with vision problems. So really adding them together just mixes it saying that .244% of people in the united states have either a vision or a hearing problem.
It doesn’t make it any more or any less people by adding them together. Therefore it’s not any more or any less probable to pick one or the other.
Ok so we know he used over 700 because he was charged more than 40. Then we take the $8.10 and divide 0.45 into it. This then gives you 18 more minutes. Then add 18 to 700 and you get 718 min.