Twelve years ago, P was half of Q's age. If the ratio of their present ages is 3:4 what will be the total of their present ages?  Select the correct option.
A) 33  B) 37  C) 29  D) 31  E) 42
E   Let present age of P and Q be 3x3x and 4x4x respectively.   Twelve years ago, P was half of Q's age   â‡’(3xâˆ’12)=1/2(4xâˆ’12)   â‡’6xâˆ’24=4xâˆ’12   â‡’2x=12   â‡’x=6   Total of their present ages   =3x+4x=7x3 +4= 
<gadget id="calculator">3 +4</gadget>
<output>7</output>
7x=7Ã—6=42
<result>E</result>
Twelve years ago, P was half of Q's age. If the ratio of their present ages is 3:4 what will be the total of their present ages?