Please help! just need answer but would also appreciate explanation

Icould really use some with this question.

Which of these numbers of simulations of an event would be most likely to produce results that are closest to those predicted by probability theory? 15, 20, 5, 10

Tim open up a new saving account with a $50 deposit and plant to deposit $20 per week into the same account.write an expression to represent the total amount in his savings account.