The birth and death rates of four countries are given below. Which one will have the least population growth rate ?
`{:("Country","Birth rate"//1000,"Death rate"//1000),(P,15,5),(Q,25,10),(R,35,18),(S,48,41):}`

Options

A. P
B. Q
C. R
D. S

Explanation

To determine which country has the least population growth rate based on the given birth and death rates, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept**: Population growth rate can be calculated using the formula:
\[ R = B - D \]
where \( R \) is the rate of population growth, \( B \) is the birth rate, and \( D \) is the death rate.

2. **Identify the Birth and Death Rates**: From the data provided:
- Country P: Birth rate = 15, Death rate = 5
- Country Q: Birth rate = 25, Death rate = 10
- Country R: Birth rate = 35, Death rate = 18
- Country S: Birth rate = 48, Death rate = 41

3. **Calculate the Growth Rate for Each Country**:
- For Country P:
\[ R_P = 15 - 5 = 10 \]
- For Country Q:
\[ R_Q = 25 - 10 = 15 \]
- For Country R:
\[ R_R = 35 - 18 = 17 \]
- For Country S:
\[ R_S = 48 - 41 = 7 \]

4. **Compare the Growth Rates**:
- Country P: \( R_P = 10 \)
- Country Q: \( R_Q = 15 \)
- Country R: \( R_R = 17 \)
- Country S: \( R_S = 7 \)

5. **Identify the Country with the Least Growth Rate**:
- The smallest value of \( R \) is for Country S, which has a growth rate of 7.

### Conclusion:
The country with the least population growth rate is **Country S**.

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