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.
Abu X + 5
Razak 2x + 10
Ahmad X
Together 4x + 15
175 - 15 = 160
160 / 4 = 40
X = 40
35% off means that now it costs 100%-35%=65% of the original price
<span>£78 ---- 65%
x------100%
x=78*100/65=120</span>£<span>
or
part/whole=0.65
78/whole=0.65
whole =78/0.65 =120 </span>£
(82,82,) (x+y) answer short