SAT两道数学题求解答!

题目

SAT两道数学题求解答!
1.At time t=0,a ball was thrown upward from an initial height of 6 feet. Until the ball hit the ground, its height, in feet, after t seconds was given by the function h above, in which c and d are positive constants. If the ball reached its maximum height of 106 feet at time t=2.5, what was the height, in feet, of the ball at time t=1?
答案是70
2.The Acme Plumbing Company will send a team of 3 plumbers to work on a certain job.The company has 4 experienced plumber and 2 trainees, how many different such teams are possible?
答案是24
哎呀傻了= =
方程：h(t)=c-(d-4t)^2

答案