Question

Mike reads 40 pages of a book in 50 minutes. David can read 10 more pages than Mike in 50 minutes. How many pages should David be able to read in 80 minutes?

Answer 1

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.

Answer 2

So, we know David can read 10 more pages than Mike in 50 minutes.

40+10= 50 

Since he reads 50 pages per 50 minutes, he reads one page per minute. 

50/50= 1

Times that by 80.

80*1= 80

He should be able to read 80 pages in 80 minutes.

I hope this helps!
~kaikers