How many ways are there to choose a committee of 7 people from a group of 10 people?

Eliza wants to make $10,000 from her investments. she finds an investment account that earns 4.5% interest. she decides to deposit $2,500 into an account. how much money will be in her account after 14 years?

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?

Ron has 8 caps and 4 of his caps are blue. thes rest of his cap are red. how many of ron's caps are red