If 20 typists can type 48 letters in 20 minutes, then how many letters will 30 typists working at the same rate complete in 1 hour?	Pick:
A) 63  B) 72  C) 144  D) 216  E) 400
20 typists can type 48 letters, so 30 typists can type = 48*30/20   48*30/20 letters can be typed in 20 mins. In 60 mins typist can type= 48*30*60/20*20= 216   216 is the answer
<result>D</result>
If 20 typists can type 48 letters in 20 minutes, then how many letters will 30 typists working at the same rate complete in 1 hour?