Rates of Change Quiz

1. If $X$ is inversely proportional to $Y$, which equation is correct?

• A. A. $X = kY$
• B. B. $X = \frac{k}{Y}$
• C. C. $X = k + Y$
• D. D. $X = Y^2$

2. A car travels 150 km in 2 hours. What is its speed?

• A. A. $300$ km/h
• B. B. $75$ km/h
• C. C. $152$ km/h
• D. D. $50$ km/h

3. An object has a mass of 20 kg and a volume of 4 m³. What is its density?

• A. A. $5$ kg/m³
• B. B. $80$ kg/m³
• C. C. $0.2$ kg/m³
• D. D. $24$ kg/m³

4. £1 = €1.15. How many euros would £200 convert to?

• A. A. €173.91
• B. B. €200
• C. C. €230
• D. D. €215

5. A curve represents a company's profit over time. Explain how to find the instantaneous rate of profit change at exactly month 6.

• A. A. Find the gradient of the chord from month 0 to month 6
• B. B. Find the gradient of the tangent to the curve at month 6
• C. C. Find the total profit up to month 6
• D. D. Find the average profit over all months