Explanation:
To solve this problem, we need to calculate the number of households earning between Rs. 1,00,000 and Rs. 2,00,000 per year based on the provided percentages and numbers.
1. Understanding the given information:
12\% of households earn less than Rs. 30,000 per year.
6\% of households earn more than Rs. 2,00,000 per year.
22\% of households earn more than Rs. 1,00,000 per year.
990 households earn between Rs. 30,000 and Rs. 1,00,000 per year.
2. Define the total number of households:
Let the total number of households be $H$.
3. Calculate the households earning between Rs. 30,000 and Rs. 1,00,000:
Households earning less than Rs. 1,00,000 include:
Households earning less than Rs. 30,000 (12\% of $H$).
Households earning between Rs. 30,000 and Rs. 1,00,000 (990 households).
Households earning more than Rs. 1,00,000 include:
Households earning between Rs. 1,00,000 and Rs. 2,00,000.
Households earning more than Rs. 2,00,000 (6\% of $H$).
Since 22\% of households earn more than Rs. 1,00,000, the percentage of households earning between Rs. 1,00,000 and Rs. 2,00,000 is:
\[
22\% – 6\% = 16\%
\]
4. Set up the equation for total households:
The sum of all percentages equals 100\%, so:
\[
12\% + \frac{990}{H} \times 100 + 16\% + 6\% = 100\%
\]
Simplifying, we get:
\[
12 + \frac{990}{H} \times 100 + 16 + 6 = 100
\]
\[
34 + \frac{990}{H} \times 100 = 100
\]
\[
\frac{990}{H} \times 100 = 66
\]
\[
\frac{990}{H} = 0.66
\]
Solving for $H$, we find:
\[
H = \frac{990}{0.66} = 1500
\]
5. Calculate the number of households earning between Rs. 1,00,000 and Rs. 2,00,000:
The number of households earning between Rs. 1,00,000 and Rs. 2,00,000 is 16\% of $H$:
\[
0.16 \times 1500 = 240
\]
Thus, 240 households earn between Rs. 1,00,000 and Rs. 2,00,000 per year.
The correct answer is (b) 240.