Answer:
No its not a right angle.
They both get their cars washed on every 60th day.
You can solve this equation by finding the lcm (least common multiple):
15 30 45 60 75 90 105
20 40 60 80 100
The lowest common multiple is 60 as it is the first multiple the two have in common.
So, in sixty days, they’ll both get their car washed again
Set up a proportion where number of times is on top and miles is on bottom:
6/1 = x/(5/6)
Cross-multiply:
6*(5/6) = 1*x
5 = x
She must run 5 times around her neighborhood.