Rahim bought 50 books for Rs.1000 from one shop and 40 books for Rs.800 from another. What is the average price he paid per book ?	Choose the correct choice from the following choices
A) 28  B) 20  C) 27  D) 29  E) 21
Average price per book   = (1000+ 800) / (50 + 40)   = 1800 / 90   = Rs.20   Answer:20
<result>B</result>
Rahim bought 50 books for Rs.1000 from one shop and 40 books for Rs.800 from another. What is the average price he paid per book ?