Question 1

What is the difference between simple interest and compound interest in Cambridge IGCSE Mathematics?

Accepted Answer

In Cambridge IGCSE Mathematics, simple interest is calculated on the original principal amount throughout the investment period. The formula is I = PRT, where I is the interest, P is the principal, R is the rate, and T is the time. Compound interest, on the other hand, is calculated on the initial principal and also on the accumulated interest from previous periods. The formula for compound interest is A = P(1 + r/n)^(nt), where A is the amount, P is the principal, r is the annual interest rate, n is the number of times interest is compounded per year, and t is the time in years.

Question 2

How do you calculate earnings using simple interest?

Accepted Answer

To calculate earnings using simple interest, you use the formula I = PRT, where I is the interest earned, P is the principal amount, R is the annual interest rate (expressed as a decimal), and T is the time in years. For example, if you invest $1,000 at an annual interest rate of 5% for 3 years, the simple interest earned would be I = 1000 * 0.05 * 3 = $150.

Question 3

Why is compound interest often considered more beneficial than simple interest?

Accepted Answer

Compound interest is often considered more beneficial than simple interest because it allows the interest to be calculated on both the initial principal and the accumulated interest from previous periods. This means that over time, the amount of interest earned grows at an increasing rate, leading to potentially higher earnings compared to simple interest, where the interest is calculated only on the original principal.

Question 4

What factors affect the amount of compound interest earned?

Accepted Answer

The amount of compound interest earned is affected by several factors: the principal amount (the initial sum of money), the interest rate (the percentage at which the money grows), the frequency of compounding (how often the interest is calculated and added to the principal), and the time period (how long the money is invested or borrowed). Increasing any of these factors will generally increase the total compound interest earned.

Question 5

How can understanding simple and compound interest help in real-life financial decisions?

Accepted Answer

Understanding simple and compound interest is crucial for making informed financial decisions. It helps in evaluating different savings and investment options, understanding loan terms, and planning for future financial goals. For instance, knowing how compound interest works can guide you in choosing investment accounts that maximize your earnings over time, while understanding simple interest can help in comparing loan offers to minimize costs.

Earnings, Simple and Compound Interest

Summary and Exam Tips for Earnings, Simple and Compound Interest

Exam Tips

Ready to Test Your Knowledge?