Answer: You need to wait at least 6.4 hours to eat the ribs.
t ≥ 6.4 hours.
Step-by-step explanation:
The initial temperature is 40°F, and it increases by 25% each hour.
This means that during hour 0 the temperature is 40° F
after the first hour, at h = 1h we have an increase of 25%, this means that the new temperature is:
T = 40° F + 0.25*40° F = 1.25*40° F
after another hour we have another increase of 25%, the temperature now is:
T = (1.25*40° F) + 0.25*(1.25*40° F) = (40° F)*(1.25)^2
Now, we can model the temperature at the hour h as:
T(h) = (40°f)*1.25^h
now we want to find the number of hours needed to get the temperature equal to 165°F. which is the minimum temperature that the ribs need to reach in order to be safe to eaten.
So we have:
(40°f)*1.25^h = 165° F
1.25^h = 165/40 = 4.125
h = ln(4.125)/ln(1.25) = 6.4 hours.
then the inequality is:
t ≥ 6.4 hours.
1) is correct.
2) is correct.
3) is correct.
4) is correct.
5) is not there.
6) is your first choice.
7) is incorrect is your second choice.
8) is your first choice.
13) is your last choice.
14) is your last choice.
15) is your third choice.
The answer is d because if you take a slither off of the left side instead of twelve you have 11 so 11+11+8+8 would equal 38. 38 isnt an option so you take another slither off so now 12 becomes 10. 10 +10+8+8= 36
