06/02/2020 (2019: AMC 8, Problem 8)

Q: Gilda has a bag of marbles. She gives 20% of them to her friend Pedro. Then Gilda gives 10% of what is left to another friend, Ebony. Finally, Gilda gives 25% of what is now left in the bag to her brother Jimmy. What percentage of her original bag of marbles does Gilda have left for herself?

Let's say that Gilda has 100 marbles to start off with. If she gives away 20% to Pedro, then she will have 80 (%) left. If she then gives 10% of what's left to Ebony, she'll have 72 (%) left. If she gives away 25% of the current amount she has, she'll have 54 marbles, or 54% left. That means the answer is E.