math
posted by ted on .
Suppose that the population of a town is described by P=0.16t^2+7.2t+100, where P is the population in thousands and t is the time in years, (
with t=o representing the year 2000).
A. what will the population be in 2010?
B. what was the population in 1995?
C. when will the population reach 52,000?
For(a) I got P=188,OOO but i do not get the answers for Band C, pLS HELP ME. am sorry for the typing error , the other time.

for B, t = 5
.16*25  7.2*5 + 100 = 68 thousand
C
52 = .16 t^2 + 7.2 t +100
solve quadratic. t will be negative of course.