All you have to do is write your question and someone will answer. For example, instead of writing "I do not understand how I find answers on here" you would ask something like what is 9*5? Then 2 people will see your question and answer. There are no pre-recorded answers, everything happens live. Hope this helps!
Using a calculator, you can find out that

and so that means

so your answer is
It should be 9:30 P.M.
7:45+ 15= 8
1 hour 35 minutes - 15= 1 hour 20
8+ 1 hour 20 minutes= 9:20
9:20+ 10= 9:30 P.M.