The ratio of the monthly income of Ravinder and his brother Jatinder in same has the ratio of the ages . Ravinder earns Rs2,00,000 and Jatinder earns 1,80,000 per month. Jatinder 45 years old . How old is Ravinder
Answers
Answer:
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
Their incomes thus become Rs. 90,000 and Rs. 120,000 respectively.
Answer:
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
Their incomes thus become Rs. 90,000 and Rs. 120,000 respectively.