rahim bought 40 books for rs . 600 from one shop and 20 books for rs . 240 from another . what is the average price he paid per book ?
"average price per book = ( 600 + 240 ) / ( 40 + 20 ) = 840 / 60 = rs . 14 answer : a"
divide(add(600, 240), add(40, 20))