How would I do exercises 1-4 plz help

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

Ammonia molecules have three hydrogen atoms and one nitrogen atom. how many of each atom arein five molecules of ammonia

After t seconds, a ball tossed in the air from the ground level reaches a height of h feet given by the equation h = 144t-16t^2. after how many seconds will the ball hit the ground before rebounding?