Answer:
Johnny's result will be identical compared with rest of class
Step-by-step explanation:
- Density is the ratio of mass to volume
- If mass increases/decreases then volume also increases/decreases proportionally. Hence density remains constant
- Johnny ate half of it's brownie. So mass of brownie becomes half of it's original mass. Volume of brownie also becomes half of it's original mass
- Density of brownie =
![((mass)_(brownie))/((volume)_(brownie))=(((mass)_(brownie))/(2))/(((volume)_(brownie))/(2))](https://img.qammunity.org/2019/formulas/chemistry/high-school/zu988qrd5azb6urzus724x4k4mmuxsgbkv.png)
- So Johnny's result will be identical compared with rest of class.