Question 89 of 480
Find the principal which amounts to N5,500 at a simple interest in 5 years at 2% per annum.
- A. N4,900
- B. N5,000
- C. N4,700
- D. N4,800
Correct Answer:
B
Explanation
To find the principal amount that will amount to N5,500 at a simple interest rate of 2% per annum over 5 years, we can use the formula for simple interest. Let's break this down step-by-step.
### Step 1: Understand the Simple Interest Formula
The formula for calculating the total amount (A) in simple interest is:
\[
A = P + I
\]
Where:
- \( A \) is the total amount after interest.
- \( P \) is the principal amount (the initial amount of money).
- \( I \) is the interest earned.
The interest \( I \) can be calculated using the formula:
\[
I = P \times r \times t
\]
Where:
- \( r \) is the rate of interest (as a decimal).
- \( t \) is the time in years.
### Step 2: Rearranging the Formula
Since we need to find the principal \( P \), we can rearrange the total amount formula:
\[
A = P + I \implies I = A - P
\]
Substituting the interest formula into this gives:
\[
A = P + (P \times r \times t)
\]
This can be simplified to:
\[
A = P(1 + rt)
\]
### Step 3: Plugging in the Values
Now, we know:
- \( A = N5,500 \)
- \( r = 2\% = 0.02 \)
- \( t = 5 \) years
Substituting these values into the equation:
\[
5,500 = P(1 + 0.02 \times 5)
\]
Calculating \( 0.02 \times 5 \):
\[
0.02 \times 5 = 0.1
\]
So, we have:
\[
5,500 = P(1 + 0.1) = P(1.1)
\]
### Step 4: Solving for Principal \( P \)
Now, we can solve for \( P \):
\[
P = \frac{5,500}{1.1}
\]
Calculating this gives:
\[
P = 5,000
\]
### Conclusion
Thus, the principal amount that will amount to N5,500 at a simple interest rate of 2% per annum over 5 years is **N5,000**.
### Explanation of Options
- **Option A: N4,900** - This is incorrect because it does not satisfy the simple interest formula when calculated with the given rate and time.
- **Option B: N5,000** - This is the correct answer as shown in our calculations.
- **Option C: N4,700** - This is also incorrect for the same reasons as above; it does not yield the correct total amount.
- **Option D: N4,800** - This option is incorrect as well; it does not satisfy the conditions of the problem.
### Revision Summary
- The formula for total amount in simple interest is \( A = P(1 + rt) \).
- Rearranging gives \( P = \frac{A}{1 + rt} \).
- Substitute the values for \( A \), \( r \), and \( t \) to find \( P \).
- The correct principal amount is N5,000, which is option B.