Susan can type 10 pages in 5 minutes. Mary can type 5 pages in 10 minutes. Working together, how many pages can they type in 30 minutes?	Pick one.
A) 11
B) 30
C) 38
D) 20
E) 75
75xplanation:   Susan can type 2 pages in 1 min   Mary can type 0.5 pages in 1 min   so, both of them work together they type 2.5 pages in 1 min   so,in 30 min they type (30 × 2.5) = 75 pages   Answer: 75
<result>E</result>
Susan can type 10 pages in 5 minutes. Mary can type 5 pages in 10 minutes. Working together, how many pages can they type in 30 minutes?