Question

A store is randomly giving away gift cards to the first 150 customers. They are giving 130 gift cards that have a value of $5 each and 15 gift cards that have a value of $50 each. The rest of the gift cards have a value of $100 each. Which is the probability that a customer will get a $100 gift card? help me !!!!!!!!!!!!!

Answer 1

If you have 150 total gift cards, and 130 are worth 5$, 15 are worth 50$, that would leave five 100$ gift cards for a sum of 150 gift cards. 
All you would do is divide the 5/150 = 30
There's a 30% chance that someone will get a 100$ gift card.