If it take some x minutes to upload some y digital photographs, it means it has an average of: x/y minutes to upload a single digital photograph. Then, to upload z photographs, you just multiply x/y by z.
Spoilers for answer:
If it take 7.2 minutes to upload 8 digital photographs, it means it has an average of: 7.2/8 = 0.9 minutes to upload a single digital photograph. This means that, by this rate, it will take 20 * 0.9 = 18 minutes to upload 20 photographs to the website.
$70.88
x/67.5=5/100
cross multiply
100x=337.5
divide 100
x=3.375 or 3.38
67.50+3.38= 70.88
Answer:

Step-by-step explanation:
Total Volume of Water = 
Volume drunk by James =
Volume drunk by Simon =
Volume drunk by Matthew = 
Volume drunk by Gilbert =
Total Volume Drunk (i.e. The Sum) = 
Volume of water Left = Total Volume of Water-Total Volume Drunk
= 
<span>2(7/9)-(1/4) = 47/36 = 1 11/36</span>
The answer to number one is C
and the answer to number two is A