The average age of 3 girls is 24 years and their ages are in the proportion 1:2:3. The age of the youngest girl is?  Choose the correct answer
A) 10 years
B) 11 years
C) 12 years
D) 13 years
E) 14 years
Total age of 3 boys = 24*3= 
<gadget id="calculator">24*3</gadget>
<output>72</output>
72   ratio of their ages= 1:2:3   Age of the youngest = 72*1/6= 
<gadget id="calculator">72*1/6</gadget>
<output>12</output>
12 years   Answer is 12 years
<result>C</result>
The average age of 3 girls is 24 years and their ages are in the proportion 1:2:3. The age of the youngest girl is?