Density of Rocks - Part A

Nguyen uses a triple beam balance to measure the mass of each rock. Read the values on the balance for rocks X, Y, and Z.

**Rock Balance Readings:**

- **Rock X:**
- Top beam: Pointer at 20
- Middle beam: Pointer at 0
- Lowest beam: Pointer at 1

- **Rock Y:**
- Top beam: Pointer at 10
- Middle beam: Pointer at 0
- Lowest beam: Pointer at 7

- **Rock Z:**
- Top beam: Pointer at 20
- Middle beam: Pointer at 0
- Lowest beam: Pointer at 6

Calculate the total mass for each rock based on these readings.