Answer:
30% of the pages are arithmetic, or 108 pages
Step-by-step explanation:
50% are on algebra = 180 pages
360 x .5 = 180
20% are on geometry = 72 pages
360 x .2 = 72
30% are on arithmetic = 108
180 + 72 + 108 = 360 pages
50% + 20% + 30% = 100%
18
6 / (1 / 3) = 6 * 3 = 18
x = 3
5 = 3x - 4
9 = 3x
a = 15