Answer:
The scale factor is 1/2
Step-by-step explanation:
Given
and 
Required
The scale factor from
to 
Take a corresponding side in both triangles.
We have:

The scale factor from
to
is:



Answer:
156
Step-by-step explanation:
209x18.50=3866.5
5700-3866.5=1833.5
1833.5÷11.75=156.04
12 students are girls and 8 are boys.