Circle Track
**Problem 1:** Amy runs around a circular track.
1. a) Find the circumference if 8 laps equal 2000m.
2. b) Find the number of laps if she runs 2500m.
3. c) Find the distance needed to reach 7.5km total after previous runs.
**Problem 2:** Given circumference of cycle track is 1500m.
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**Step 1a:**
1. The total distance for 8 laps is 2000m.
2. Circumference $C$ is distance per lap, so $C = \frac{2000}{8} = 250$ meters.
**Step 1b:**
1. Given distance run is 2500m.
2. Number of laps $n = \frac{\text{distance}}{\text{circumference}} = \frac{2500}{250} = 10$ laps.
**Step 1c:**
1. Total target distance is 7.5 km = 7500 m.
2. Distance already run is $2000 + 2500 = 4500$ m.
3. Remaining distance $= 7500 - 4500 = 3000$ m = 3 km.
**Step 2:**
1. Circumference $C = 1500$ m.
2. Using formula $C = 2\pi r$, solve for radius $r$:
$$r = \frac{C}{2\pi} = \frac{1500}{2\pi} = \frac{1500}{6.2832} \approx 238.73 \text{ m}$$
3. Diameter $D = 2r = 2 \times 238.73 = 477.46$ m.
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**Final answers:**
- 1a) Circumference = 250 m
- 1b) Laps run = 10
- 1c) Distance needed = 3 km
- 2) Radius $\approx$ 238.73 m, Diameter $\approx$ 477.46 m