The age of father 10 years ago was thrice the age of his son. Ten years hence, father's age will be twice that of his son. What is the ratio of their present ages?  Choose the correct answer.
A) 7:3
B) 3:7
C) 4:8
D) 8:4
E) 2:3
Let age of the son before 10 years =x and   age of the father before 10 years =3x   (3x+20)=2(x+20)⇒x=20   7:3ge of the son at present =x+10=20+10= 
<gadget id="calculator">20+10</gadget>
<output>30</output>
30   7:3ge of the father at present=3x+10=3×20+10=70   Required ratio =70:30=7:3   7:3nswer is 7:3.
<result>A</result>
The age of father 10 years ago was thrice the age of his son. Ten years hence, father's age will be twice that of his son. What is the ratio of their present ages?