Given: h(t) = 25 - a·t²
h(0.5) = 21
Find: t such that h(t) = 0
Solution: h(0.5) = 25 - a·0.5² = 21
25 - 21 = a/4
4·4 = a = 16
Then
h(t) = 25 - 16t²
We want h(t) = 0, so
0 = 25 - 16t²
16t² = 25
t² = 25/16 = (5/4)²
t = 5/4 = 1.25
It takes 1.25 seconds for the entire 25 ft drop.
40
P(42) = (6/7)(42) + 4 = 36 + 4 = 40
C) 0.75. If 6/8 of the gifts were toys, that’s 3/4 which equals 75%.