The average age of a group of 10 students is 20 years. If 2 more students join the group, the average age increases by 1 year. The average age of the new students is
Choose one
A) 23 B) 21 C) 19.5 D) 20 E) 22.5
Total age of 10 students = 10 * 20= 
<gadget id="calculator">10 * 20</gadget>
<output>200</output>
200 and the total age of 16 students= 21*15= 
<gadget id="calculator">21*15</gadget>
<output>315</output>
315.   Let the average age of 2 new students be x.   Therefore total age of the new students= 2x.   So total age of 12 student =200 +5x=315, x=23   Hence, the correct answer is 23.
<result>A</result>
The average age of a group of 10 students is 20 years. If 2 more students join the group, the average age increases by 1 year. The average age of the new students is