In September, the incomes of Kamal, Amal and Vimal are in the ratio . They rent a house together, and Kamal pays , Amal pays and Vimal pays of their respective incomes to cover the total house rent in that month. In October, the house rent remains unchanged while their incomes increase by , and , respectively. In October, the percentage of their total income that will be paid as house rent, is nearest to
In September, the incomes of Kamal, Amal and Vimal are in the ratio . They rent a house together, and Kamal pays , Amal pays and Vimal pays of their respective incomes to cover the total house rent in that month. In October, the house rent remains unchanged while their incomes increase by , and , respectively. In October, the percentage of their total income that will be paid as house rent, is nearest to
Solution
Let their September incomes be , , and respectively, where is some positive number.
Each person pays a percentage of their income toward rent:
Kamal pays: of
Amal pays: of
Vimal pays: of
Total house rent =
The house rent stays the same in October, so this amount remains constant.
| Person | Sept | % Increase | Multiplier | October |
|---|---|---|---|---|
| Kamal | $8k | 10% | 1.10 | $8.8k |
| Amal | $6k | 12% | 1.12 | $6.72k |
| Vimal | $5k | 15% | 1.15 | $5.75k |
| Total | $21.27k |
Now we have:
- House rent (unchanged):
- Total income in October:
Percentage formula:
Percentage =
Percentage =
Therefore:
This makes intuitive sense: their incomes all increased, but the rent stayed the same, so rent should represent a smaller percentage of their total income compared to September.