Answer:
2400 cm
Step-by-step explanation:
The milky way has diameter of 100000 light years.
![100000\ ly=24\ cm\\\Rightarrow 1\ ly=(24)/(100000)\ cm](https://img.qammunity.org/2020/formulas/physics/high-school/w7xci1ipuwv7ghpixbhjhqpjdxlq6z0ecj.png)
The local group is the collection of galaxies which includes the milky way.
10 million light years is the diameter of the local group.
![10* 10^6\ ly=10* 10^6* (24)/(100000)\ cm\\\Rightarrow 10* 10^6\ ly=2400\ cm](https://img.qammunity.org/2020/formulas/physics/high-school/j2mvs1ue3rgdo5x9ggo4gt5n2a7emwa56b.png)
Hence, the diameter of the scale model of the local group would be 2400 cm