Answer:
(b) 67
Step-by-step explanation:
A solution to the differential equation describing the temperature according to Newton's Law of Cooling could be written as ...
T = (final temp) + (initial difference)×(decay factor)^t
where the decay factor is the fraction of change during 1 unit of time period t.
__
Here, the initial difference of 100-25 = 75 degrees decays to 90-25 = 65 degrees in 1 minute. So, the units of t are minutes, the decay factor is 65/75, the initial difference is 75 degrees, and the final temperature is 25 degrees. That lets us write the equation as ...
T = 25 +75(65/75)^t
Then for t=4, the temperature is ...
T = 25 +75(13/15)^4 ≈ 67.3 . . . . degrees
After 4 minutes the temperature of the coffee is about 67 degrees.
The answer is $46.22, you do $42.80 plus 8% on a calculator
Answer:
AAS
Step-by-step explanation:
HEHE
<span>The answer should be 4.5 because they used AT LEAST 32 miles per gallon. So, 144/32=4.5 and since it's AT LEAST 32, 4.5 is the max amount used.</span>
Answer:
x = 6 months.
The equation is given by $45 + ($49.45 × x) = ($56.95 × x).
Step-by-step explanation:
i) Let x be the number of months of Internet Service purchased till the Fast
Internet charges and Quick Internet charges become the same.
ii) Charges for Fast Internet for x months is given by $45 + ($49.45 × x)
iii) Charges for Quick Internet for x months is given by ($56.95 × x)
iv) According to the first statement we will now equate the equations in ii)
and iii) and solve for x.
Therefore, $45 + ($49.45 × x) = ($56.95 × x)
45 + 49.45 x = 56.95 x
Therefore (56.95 - 49.45) x = 45
7.50 × x = 45
Therefore x = 45 ÷ 7.5 = 6
