Sam wrote 7 letters on Tuesday and 3 letters on Wednesday. How many letters did he write on average per day? Choose the correct choice from the following choices:
A) 10 B) 4 C) 21 D) 3 E) 5
(7 + 3)/2= 
<gadget id="calculator">(7 + 3)/2</gadget>
<output>5</output>
5   The correct answer is 5
<result>E</result>
Sam wrote 7 letters on Tuesday and 3 letters on Wednesday. How many letters did he write on average per day?