Answer:
t = 17.4 minutes
Step-by-step explanation:
p = a(1/2)^(t/h)
121 = 900(1/2)^(t/6)
Divide both sides by 900
0.1344444444 = (1/2)^(t/6)
Take the log of both sides
log0.1344444444 = (t/6)log(1/2)
Divide both sides by log(1/2)
log0.1344444444 / log(1/2) = t/6
multiply both sides by 6
6 * log0.1344444444 / log(1/2) = t
use calculator
17.369507726516199 = t
rounded
t = 17.4 minutes
