Let us look at a real-life physics problem using our standard SI base units. Imagine Rahul is riding his bicycle down a straight road. He measures the distance he covers as 100 metres ($100\text{ m}$) and it takes him a time of 20 seconds ($20\text{ s}$) to reach his friend's house. What is his speed in SI units? Step 1: Identify the given quantities in their correct SI base units. Distance ($d$) = $100\text{ m}$ (Unit is metre, which is the SI base unit for length). Time ($t$) = $20\text{ s}$ (Unit is second, which is the SI base unit for time). Step 2: Write down the formula for speed. Speed ($v$) = Distance / Time ($v = d / t$). Step 3: Substitute the numerical values into the formula along with their units. $v = 100\text{ m} / 20\text{ s}$. Step 4: Perform the division for the numbers and units. $100 \div 20 = 5$. The units become metres divided by seconds ($\text{m/s}$). Final Answer: Rahul's speed is $5\text{ m/s}$ (metres per second), which is derived directly from the SI base units of length and time.