Answer:
Step-by-step explanation:
It is given that a meteorologist is using a Doppler radar to find out the distance of the storm as it passes using a polar grid.
The origin of the radar screen is its center.
And the distance between each ring is 10 miles from the center.
So let :
r = radius
h and k = be the coordinates of the center.
So the equation of a circle is :

Now the equation of the fourth circle when the radius changes by 10 miles is :
Answer:
3/5
Step-by-step explanation:
60/100 can be reduced down to 6/10 by dividing by 10, and then you can simplify even more by dividing 6/10 by 2, which leaves you with 3/5.
I hope this helps :)