1.
Bruce invests $3,500 at 8% p.a. simple interest, for a period of time, to produce $210 interest. For how long did he invest the money?
Correct Answer
A. 1.3 years
Explanation
Bruce invested $3,500 at an interest rate of 8% per year. The interest earned on this investment was $210. To find the time period for which he invested the money, we can use the formula for simple interest: Interest = Principal × Rate × Time. Plugging in the given values, we have $210 = $3,500 × 0.08 × Time. Solving for Time, we get Time = $210 / ($3,500 × 0.08) = 1.3 years. Therefore, Bruce invested the money for 1.3 years.
2.
Daniel invests $5,000 earns $6,000 simple interest in 12 years. Calculate the interest rate.
Correct Answer
C. 10%
Explanation
Daniel invested $5,000 and earned $6,000 in interest over a period of 12 years. To calculate the interest rate, we can divide the interest earned ($6,000) by the principal amount invested ($5,000) and then divide the result by the number of years (12). This gives us a decimal value of 0.1. To convert this to a percentage, we multiply by 100, which gives us 10%. Therefore, the interest rate is 10%.
3.
Abbie invests $2,500 at 8% p.a. simple interest for a period of time and receives $50 interest. For how long (in months) did she invest the money?
Correct Answer
D. 3 months
Explanation
Abbie invested $2,500 at a simple interest rate of 8% per annum and received $50 in interest. To find the time period of the investment, we can use the formula: Interest = Principal x Rate x Time. Plugging in the given values, we have $50 = $2,500 x 0.08 x Time. Solving for Time, we find that Time = 3 months. Therefore, Abbie invested the money for 3 months.
4.
Jasmeen invests $400 and earns $80 simple interest in 2 years. Calculate the interest rate.
Correct Answer
D. 10%
Explanation
Jasmeen invested $400 and earned $80 in 2 years. To calculate the interest rate, we can use the formula: Interest = Principal × Rate × Time. Plugging in the given values, we have 80 = 400 × Rate × 2. Solving for Rate, we get Rate = 80 / (400 × 2) = 0.1, which is equal to 10%. Therefore, the interest rate is 10%.