Quick! need the answer, anyone know?

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?

Will give a: 122 b: 90 c: 48 d: 180

Two cities a and b are 1400km apart and lie on the same n-s line. the latitude of city a is 23 degrees. what is the latitude of city b. the radius of the earth is approximately 6400km.