1. **State the problem:**
A train travels a track measured as 270 km (nearest 10 km assumed initially) in 110 minutes (nearest 5 minutes). We want to check if the average speed could be greater than 160 km/h.
2. **Convert time to hours:**
Since 110 minutes is measured to the nearest 5 minutes, the actual time $t$ lies in the interval:
$$105 \leq t \leq 115 \text{ minutes}$$
Convert to hours:
$$\frac{105}{60} \leq t \leq \frac{115}{60}$$
$$1.75 \leq t \leq 1.9167 \text{ hours}$$
3. **Determine distance bounds:**
Jake assumes the track length is 270 km measured to the nearest 10 km, so the actual distance $d$ lies in:
$$265 \leq d \leq 275 \text{ km}$$
4. **Calculate maximum possible average speed:**
Average speed $v = \frac{d}{t}$.
To check if $v > 160$ km/h is possible, use the maximum distance and minimum time:
$$v_{max} = \frac{275}{1.75} = 157.14 \text{ km/h}$$
5. **Interpretation:**
Since $157.14 < 160$, the average speed could not have been greater than 160 km/h under these assumptions.
6. **Part (b) explanation:**
If the track was actually measured to the nearest 5 km, the distance bounds become:
$$267.5 \leq d \leq 272.5 \text{ km}$$
This reduces the uncertainty in distance, making the maximum possible speed closer to:
$$\frac{272.5}{1.75} = 155.71 \text{ km/h}$$
This smaller range confirms the average speed is even less likely to exceed 160 km/h.
**Final answer:**
No, the average speed could not have been greater than 160 km/h.
Average Speed A1040B
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.