Ten years ago, Q was half of R's age. If the ratio of their present ages is 3:4, what will be the total of their present ages?  Choose the correct choice from the following answers.
A) 5  B) 10  C) 15  D) 20  E) 25
Let present age of P and Q be x and 2x respectively.   Ten years ago, Q was half of R's age   ⇒(x−10)=2(2x−10)   ⇒x−10=4x−20   ⇒3x=10   ⇒x=10/3   Total of their present ages=x+2x   =&gt;10/3 + 20/3   =&gt;30/3= 
<gadget id="calculator">30/3</gadget>
<output>10</output>
&gt;10   ANSWER:10
<result>B</result>
Ten years ago, Q was half of R's age. If the ratio of their present ages is 3:4, what will be the total of their present ages?