Billy deleted 64 songs from his mp3 player. if the ratio of songs he deleted to songs he kept was 8: 3, how many songs did he originally have on his mp3 player?

Astandard deck of cards contains 52 cards. one card is selected from the deck. (a) compute the probability of randomly selecting a seven or king. (b) compute the probability of randomly selecting a seven or king or jack. (c) compute the probability of randomly selecting a queen or spade.

Can someone me and do the problem plz so i can understand it more better

Aprojectile is thrown upward so that its distance above the ground after t seconds is given by the function h(t) = -16t2 + 704t. after how many seconds does the projectile take to reach its maximum height?