Question

Pritam got 28% raise in the total income. if new income is 2,00,000 find. her total income.​

Answer 1

Step-by-step explanation:

Let the incomes of Aryan and Babban be 3x and 4x respectively.

Similarly, their expenditures would be 5y and 7y respectively.

Since each saves Rs. 15000, we get

3x−5y=15000...(1)

4x−7y=15000...(2)

This can be written in matrix form as [

3

4

−5

−7

][

x

y

]=[

15000

15000

]

R

2

→R

2

−

3

4

R

1

We get

⎣

⎢

⎡

3

0

−5

3

−1

⎦

⎥

⎤

[

x

y

]=[

15000

−5000

]

R

2

→R

2

×−3

We get [

3

0

−5

1

][

x

y

]=[

15000

15000

]

R

1

→R

1

+5R

2

We get [

3

0

0

1

][

x

y

]=[

90000

15000

]

R

1

→R

1

×

3

1

We get [

1

0

0

1

][

x

y

]=[

30000

15000

]

∴x=30000