A is three times as old as B. C was twice-as old as A four years ago. In four years' time, A will be 31. What are the present ages of B and C ?	Choose the correct choice from the following:  A) 9, 46  B) 9, 50  C) 10, 46  D) 10, 50  E) 10, 56
Explanation:   We have : A = 3B ...(i) and   C - 4 = 2 (A - 4) ...(ii)   Also, A + 4 = 31 or A= 31-4= 
<gadget id="calculator">31-4</gadget>
<output>27</output>
27.   Putting A= 27 in (i), we get: B = 9.   Putting A = 27 in (ii), we get C = 50.   Answer: 9, 50
<result>B</result>
A is three times as old as B. C was twice-as old as A four years ago. In four years' time, A will be 31. What are the present ages of B and C ?