The savings of Chetan and Dinesh are 3x – 5y and 4x – 7y respectively.
3x – 5y = 200 --- (1)
4x – 7y = 200 --- (2)
Multiplying (1) by 7 and (2) by 5 and subtracting the resultant equation (2) from resultant equation (1), we get x = 400.
The incomes of Chetan and Dinesh are 3x = Rs.1200 and 4x = Rs.1600 respectively.