Indeed, a fare of $40 is a fair charge for the cab ride.
Explanation
Sheri's cab fare totaled $32, with a gratuity rate of 20%.
The gratuity amount is: 
Thus, the total cab fare including gratuity is: 
Since Sheri issued a $40 check to the cab driver, it indicates she provided ($40 - $38.40) or an extra $1.60 to the cab driver. Consequently, the $40 payment is reasonable for the cab fare.
The factors of 36 include: 1, 2, 3, 4, 6, 9, 12, 18, 36.
For 34, the factors are: 1, 2, 17, 34.
The factors of 22 are: 1, 2, 11, 22.
The greatest common factor (GCF) is 2.
The watch is less expensive in Geneva, Switzerland by £20. Step-by-step explanation: To identify the city where the watch is cheaper, we need to convert the watch's price to the same currency. Since pounds are utilized in part b of the question, using this currency would simplify the calculations. In Geneva, the watch's price is 193.75 CHF from our conversion: £1 = 1.55 CHF, thus, £x = 193.75 CHF. By cross-multiplying, we solve for x: (193.75 * 1) / 1.55 = 193.75/1.55 = £125. This demonstrates that the watch is cheaper in Geneva and more expensive in Manchester. To find out by how much, we simply deduct the Geneva price from the Manchester price: 145 - 125 = £20 cheaper.
A.) P(t) = P0e^(kt)
P(20/60) = 40 e^(20k/60)
80 = 40 e^(k/3)
e^(k/3) = 80/40 = 2
k/3 = ln(2)
k = 3ln(2)
b.) P(8) = 40(2)^24 = 40(16777216) = 671088640 cells
d.) Rate of change = e^(8k) = e^(8(3ln(2))) = e^(24ln(2)) = e^(16.6355) = 16777216 cells/hour
e.) P(t) = 40(2)^(3t); t in hours
1,000,000 = 40(8)^t
25,000 = 8^t
ln(25,000) = t ln(8)
t = ln(25,000)/ln(8) = 4.87 hours
Part a) When a page is scaled down to 80%, how much enlargement is necessary to bring it back to its original size?
Let
x---------> the percent enlargement
Given the original size is 100%
This means:
x*80%=100%
x=(100%/80%)
x=1.25--------> 1.25=(125/100)=125%
Thus,
The answer to Part a) is
The percent enlargement required is 125%
Part b) Estimate how many successive copies of a page are needed to make the final copy less than 15% of its original size.
Since the photocopy machine reduces sizes to 80% of the original
Therefore:
Copy N 1
0.80*100%=80%
Copy N 2
0.80*80%=64%
Copy N 3
0.80*64%=51.2%
Copy N 4
0.80*51.2%=40.96%
Copy N 5
0.80*40.96%=32.77%
Copy N 6
0.80*32.77%=26.21%
Copy N 7
0.80*26.21%=20.97%
Copy N 8
0.80*20.97%=16.78%
Copy N 9
0.80*16.78%=13.42%-------------> 13.42% < 15%
Therefore,
The answer to Part b) is
The necessary number of copies to achieve this is 9
