David can read 50 pages in 50 minutes.
(50 pages)/(50 minutes) = 1 page/minute
Since David reads 1 page per minute,
in 80 minutes David can read 80 pages.
9 dollars represents 90% of the cost. Divide 9 by 0.90 to get the original price, 10 dollars
Answer:
13 to 25
13:25

Step-by-step explanation:
All of these show the ratio 13/25
Hope this helps!