AFCAT I 16 Feb 2019 Paper

(a) Let the monthly income of B be Rs. x.
Then, Monthly income of A= Rs. 2x and
Saving of A=5000 x 4/(4 +1)
= Rs. 4000
Saving of B = Rs. 1000
Now, we have
(2x - 4000) / (x-1000) = 5/3
⇒ 6x -12000 = 5 x - 5000
x = Rs.7000
So, Monthly income of B = 7000