Answer:
Light collecting area of 6 mm telescope is 4 times greater than light collecting area of 3 mm telescope.
Step-by-step explanation:
Diameter of 1st telescope = 6 mm
Diameter of 2nd telescope = 3 mm
Light collecting area of telescope is given as
![A=(\pi D^(2))/(4)](https://img.qammunity.org/2021/formulas/physics/high-school/sm97v5zvzmb0toffmmx3u6zy8bxranrlnn.png)
For 1st telescope
![A_(1)=(\pi (6)^(2))/(4)\\\\A_(1)=9\pi](https://img.qammunity.org/2021/formulas/physics/high-school/wbmclfkgna75eyzp8maskq8cyfh1146mb4.png)
For 2nd telescope
![A_(2)=(\pi (3)^(2))/(4)\\\\A_(1)=(9)/(4)\pi](https://img.qammunity.org/2021/formulas/physics/high-school/cn9ow1f6eo1foohcfqw0wjyu48s4wurbxt.png)
![A_(1)=(1)/(4)A_(2)\\\\A_(2)=4A_(1)](https://img.qammunity.org/2021/formulas/physics/high-school/urjev9gwt1kba8t5lmw67altzmkyfi5t4d.png)
Which means light collecting area of 6 mm telescope is 4 times greater than light collecting area of 3 mm telescope.