The ratio of ages of A and B 1 year ago was 3:4.After 1 year it will be 5:6.what is the present age of A.	Choose the correct choice from the following answers.
A) 1	B) 2	C) 3	D) 4	E) 5
Solution:Let x be the age of A and y be the age of B   hen ratio of their ages one year ago (x-1):(y-1)=3:4   =&gt;(x-1)/(y-1)=3/4............(1)   Ratio of their ages after one year (x+1):(y+1)=5:6   =&gt;(x+1)/(y+1)=5/6..........(2)   Solving (1) and (2)   (1)=&gt;4(x-1)=3(y-1)   =&gt;4x-4=3y-3   =&gt;4x-3y=1.......................(3)   (2)=&gt;6(x+1)=5(y+1)   =&gt;6x-5y=-1......................(4)   3*(3) - 2*(4)   12x - 9y=3 -   12x - 10y12  - 9= 
<gadget id="calculator">12  - 9</gadget>
<output>3</output>
3 -   12x - 10y=-2   ___________   y = 5   ___________   (3)=&gt;4x-15=1   =&gt;4x=16   =&gt;x=16/4= 
<gadget id="calculator">16/4</gadget>
<output>4</output>
4   Answer 4
<result>D</result>
The ratio of ages of A and B 1 year ago was 3:4.After 1 year it will be 5:6.what is the present age of A.