The average of seven numbers is 18. The average of first three numbers is 14 and the average of last three numbers is 23. What is the middle number?  Pick:	A) 25	B) 27	C) 15	D) 32	E) 34
The total of seven numbers = 7X18 = 126   The total of first 3 and last 3 numbers is = 3 X 14+3 X 23 = 111   So, the middle number is  (126 - 111 )= 
<gadget id="calculator"> (126 - 111 )</gadget>
<output>15</output>
15   15
<result>C</result>
The average of seven numbers is 18. The average of first three numbers is 14 and the average of last three numbers is 23. What is the middle number?