The average age of 2 boys is 25 years and their ages are in the proportion 3:5:7. The age of the youngest boy is?  Choose the correct choice from the following answers.
A) 10years  B) 15years  C) 20years  D) 25years  E) 18years
Total age of 2 boys = 25*2= 
<gadget id="calculator">25*2</gadget>
<output>50</output>
50   ratio of their ages= 3:5:7   10yearsge of the youngest = 50*3/15= 
<gadget id="calculator">50*3/15</gadget>
<output>10</output>
10 years   10yearsnswer is 10years
<result>A</result>
The average age of 2 boys is 25 years and their ages are in the proportion 3:5:7. The age of the youngest boy is?