3053.63=πr^2h

what is h?

Can someone explain the elimination method to me for this problem?

You are cycling around europe with friends. you book into a hostel and you ask the owner what the ratio of men to women is currently staying there. there are 24 men and 6 women. what is the ratio of men to women in its simplest form?

If you had $1,900,000, how many days would it take you to spend all if you spent $1 a second. (there are 86,400 seconds in a day)