Question

The ratio of incomes of two persons is 9 : 7 and

the ratio of their expenditures is 4 : 3. If each of

them manages to save Rs. 2000 per month, find

their monthly incomes.

Answer 1

Let the gross income multiplier = x

Let the expenditure multiplier = y

=> 9x - 4y = 200 ......1
      7x - 3y = 200 ......2

Multiplying the 1st equation by -3 and the 2nd equation by 4, we get:-

-27x + 12y = -600 .............3
28x - 12y = 800  ...........4

Solving 3 and 4, we get;
x = 200

Now, 9*200 = Rs.1800 is one income
        7*200 = Rs.1400 is the other income

Hope it helps!

Answer 2

Answer:

Let the income of the first person = 9x

Income of the second person = 7x

Let the expenditure of first person = 4y

Expenditure of the second person = 3y

According to Question ,

Each of them manages to save ₹2000 per month....

➪So, 9x - 4y = 2000....(1)

➪7x - 3y = 2000....(2)

➪ Multiply 3 to (1) and 4 to (2)....

we get,

➪27x - 12y = 6000

➪28x - 12y = 8000 [ here the signs change ]

- x = - 2000

➪x = 2000

Substitute x = 2000 in (1) ,

➪9 (2000) - 4y = 2000

➪18000 - 4y = 2000

➪18000 -2000 = 4y

➪16000 = 4y

➪ y = 4000

❦ x = 2000 ; y = 4000

______________________________________

➪ Income of 1 st person = 9x = rupees 18000

➪ Income of 2nd person = 7x= rupees 14000

Step-by-step explanation: