A is older than B by 5years. Seven years hence, thrice A's age shall be equal to four times that of B. Find their present ages. Choose the correct choice from the following.
A) 14, 7
B) 10, 5
C) 13, 8
D) 12, 8
E) 8, 12
Explanation:   Let the present ages of A and B be 'a' and 'b' respectively.   3(a + 7)= 4( (b +7 ) --- (1) =&gt;3a-4b=7 -------(1)   a-b = 5 -------(2) Solving (1) and (2) we get b=8   Substituting b = 8 in second equation, we get a= 13. Answer : C   =&gt; 2a = 32 =&gt; a = 16.   Answer: 13, 8
<result>C</result>
A is older than B by 5years. Seven years hence, thrice A's age shall be equal to four times that of B. Find their present ages.