The ratio of the monthly incomes of A and B is 3:4. The ratio of monthly expenditures of A and B is 4:5. Which of the below is a possible value of the ratio of their savings?
9:10
3:4
13:20
4:5
How to form a equation for solving this?
2 answers
friday
A makes 3x
B makes 4x
A spends 4y
B spends 5y
So,
A saves 3x-4y
B saves 4x-5y
So, can you solve
(3x-4y)/(4x-5y) = 9/10 ?
10(3x-4y) = 9(4x-5y)
30x-40y = 36x-45y
6x = 5y
Can't happen
try the other fractions.
B makes 4x
A spends 4y
B spends 5y
So,
A saves 3x-4y
B saves 4x-5y
So, can you solve
(3x-4y)/(4x-5y) = 9/10 ?
10(3x-4y) = 9(4x-5y)
30x-40y = 36x-45y
6x = 5y
Can't happen
try the other fractions.