B) 14.
If you start with subtracting the 8 pages from 50, you get 42 remaining pages. Then it says 2/3 of the REMAINING pages so you divide 42 into thirds. 42/3=14. You want 2/3 of that, so you multiply the 14 by two to get 28 (it's like there are three piles of 14 pages and you want only 2 out of the three piles). So now you've used 28 pages + the original 8. You've used a TOTAL of 36 pages. Subtract 36 from 50 and you get 14 left.