Hi there! The answer is 210 pages.
We can find our answer by looking at the proportions:
20 % is 42 pages.
10 % is 21 pages (42 / 2).
100% is 210 pages. (21 × 10).
True.
E.g. (x-1)(x-2) versus 100(x-1)(x-2)
They have same roots of x= 1 or 2, but the second equation is 100 times stretching of the first one vertically
All work is show in the picture below.
The correct answer is A
2×2×5×5×5×7
4 × 25 × 7
700