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 answer:
A) 9, 46  B) 9, 50  C) 10, 46  D) 10, 50  E) 10, 60
B = x   A = 3x-4   c = 6x-4   so. given A=3x-4 = 31   after 4 year A=3x = 31 -4= 
<gadget id="calculator">31 -4</gadget>
<output>27</output>
27   9, 50= x = 9   c = 6*9 -4= 
<gadget id="calculator">6*9 -4</gadget>
<output>50</output>
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 ?