The incomes of A, B, C are in the ratio of 12: 9: 7 and their spending...
Given:
Incomes ratio of A: B: C = 12: 9: 7
Spending ratio of A: B: C = 15: 9: 8
A saves 25% of his income
To find:
Ratio of savings of A, B, and C
Solution:
Let the incomes of A, B, and C be 12x, 9x, and 7x respectively.
And, let the spending of A, B, and C be 15y, 9y, and 8y respectively.
Since A saves 25% of his income, his savings would be 25% of 12x = 3x
Now, the remaining income of A after savings = 12x - 3x = 9x
The savings of B and C can be found by subtracting their spending from their incomes.
Savings of B = 9x - 9y = x(9 - y)
Savings of C = 7x - 8y = x(7 - 8/3y)
Now, we can find the ratio of savings of A, B, and C as follows:
Ratio of savings of A, B, and C = 3x : x(9 - y) : x(7 - 8/3y)
Simplifying the ratio, we get:
Ratio of savings of A, B, and C = 3 : 3(9 - y)/x : 3(7 - 8/3y)/x
Ratio of savings of A, B, and C = 3 : 27/4 - 3y/4 : 21/4 - 2y/3
Multiplying the ratio by 4 to eliminate fractions, we get:
Ratio of savings of A, B, and C = 12 : 27 - 3y : 21 - 8y/3
Multiplying the ratio by 3 to eliminate fractions, we get:
Ratio of savings of A, B, and C = 36 : 81 - 9y : 63 - 8y
Ratio of savings of A, B, and C = 36 : 81 : 63 - 8y + 9y
Ratio of savings of A, B, and C = 36 : 81 : 63 + y
Given that the incomes ratio of A, B, and C are in the ratio 12: 9: 7
Thus, we can take y = 7x/8 and substitute in the ratio of savings.
Ratio of savings of A, B, and C = 36 : 81 : 63 + 7x/8
Ratio of savings of A, B, and C = 36 : 81 : 135/8
Multiplying the ratio by 8 to eliminate fractions, we get:
Ratio of savings of A, B, and C = 288 : 648 : 135
Simplifying the ratio, we get:
Ratio of savings of A, B, and C = 16 : 36 : 7
Hence, the ratio of savings of A, B, and C is 15:18:11.
The incomes of A, B, C are in the ratio of 12: 9: 7 and their spending...
Let income be X
Incomes are :
A: 12/28 X; B: 9/28X; C: 7/28X
Let Spent be Y
Spent is:
A: 15/32 Y; B: 9/32 Y; C: 8/32 Y
Solving these equations we get the value of Y in terms of X
Y=24/35 X
Find the values of spent in terms of X
A: 9/28 X; B: 27/140 X; C: 6/35 X
subtract the values of spent from the incomes
taking the ratio of the obtained values gives us the answer