Mr Thomas wants to leave the fund raiser with at least $50 in his pocket.
He has $100 dollars when he goes to the fund raiser.
At the fund raiser you can buy a raffle ticket so you can win prizes.
A raffle ticket costs $2.50
So a quick way to do this is
50/2.50
Which is 20, so Mr Thomas should buy 20 raffle tickets if he wants to leave with $50.
