Binson's answer to Your Mum's Secondary 4 E Maths Singapore question.

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Binson
Binson's answer
11 answers (A Helpful Person)
1st
To find the value of x, the interest rate, we can use the formula for compound interest:

Final Amount = Principal * (1 + (Rate/100))^Time

In this case, the final amount is $11,000, the principal is $10,000, and the time is 5 years. We need to solve for the rate, denoted as x.

$11,000 = $10,000 * (1 + (x/100))^5

Dividing both sides by $10,000:

1.1 = (1 + (x/100))^5

Taking the fifth root of both sides:

1.1^(1/5) = 1 + (x/100)

Subtracting 1 from both sides:

1.1^(1/5) - 1 = x/100

Multiplying both sides by 100:

100 * (1.1^(1/5) - 1) = x

Using a calculator:

100 * (1.1^(1/5) - 1) ≈ 4.14

Therefore, the value of x, the interest rate, is approximately 4.14%.