1. **Stating the problem:** We need to find the measurement reading from a Vernier caliper with three scales: a top scale in inches (0.001 in divisions), a middle scale with numbers 20 to 70, and a bottom scale in millimeters (0.05 mm divisions). 2. **Understanding the scales:** - The top scale increments by 0.001 inches. - The middle scale shows a primary scale with numbers 20, 30, 40, 50, 60, 70 and a '2' above it, indicating the main reading in some unit. - The bottom scale is in millimeters with 0.05 mm divisions. 3. **Reading the main scale:** The pointer is between 3 and 4 on the middle scale, closer to 4. This suggests the main scale reading is approximately 3 units plus some fraction. 4. **Reading the Vernier scale:** The vernier scale alignment is near mark 10 on the top scale (0.001 in divisions). This means the vernier reading is $10 \times 0.001 = 0.010$ inches. 5. **Calculating the final reading:** Assuming the middle scale units correspond to inches, the main scale reading is 3 inches. Adding the vernier scale reading: $$\text{Final reading} = 3 + 0.010 = 3.010 \text{ inches}$$ 6. **Converting to millimeters (optional):** Since 1 inch = 25.4 mm, $$3.010 \times 25.4 = 76.454 \text{ mm}$$ **Final answer:** - Main scale reading: 3 inches - Vernier scale reading: 0.010 inches - Final reading: 3.010 inches (or 76.454 mm)