The average age of seven persons sitting in a row facing east is 28 years. If the average age of the first three persons is 25 years and the average age of the last three persons is 32 years, then find the age of the person sitting in the middle of the row?  Choose one:
A) 9 years B) 29 years C) 25 years D) 19 years E) 17 years
Total age seven persons = (28 * 7)years   Total age of the first three persons and the last three persons are (25 * 3) years and (32 * 3) years respectively.   Age of the person sitting in the middle of the row = 28 * 7 - 25 * 3 - 32 * 3 = 196 - 75 - 96= 
<gadget id="calculator">196 - 75 - 96</gadget>
<output>25</output>
25 years.   ANSWER:25 years
<result>C</result>
The average age of seven persons sitting in a row facing east is 28 years. If the average age of the first three persons is 25 years and the average age of the last three persons is 32 years, then find the age of the person sitting in the middle of the row?