UPSC Civil Services 2015 Prelims General Studies Paper II

Let the Income of Peter and Paul are 4x and 3x
Let the Expenses of Peter and Paul are 3y and 2y
So, According to question
4x – 3y = 6000 ... (i)
3x – 2y = 6000 ... (ii)
Now, From equation (i) and equation (ii)
4x – 3y = 3x – 2y
∴ x = y ⇒ y = x
Now, put the value of y in equation (i), we get
Þx = 6000
∴ 4x = 24000
3x = 18000
Monthly Incomes of Peter and Paul are ₹ 24000 and ₹ 18000 respectively.