Answer:
While both types of interest will grow your money over time, there is a big difference between the two. Specifically, simple interest is only paid on principal, while compound interest is paid on the principal plus all of the interest that has previously been earned.
To find the rate in miles per hour, divide the miles by the hours.
(1 1/2 miles)/(3/5 hour) =
= 3/2 miles * (5/3 hour)
= 5/2 mph
= 2 1/2 mph
Her walking rate is 2 1/2 mph.
(4 1/2 miles) / ( 2 1/2 mph) =
= 9/2 miles / (5/2 mph)
= 9/2 * 2/5 hours
= 9/5 hours
= 1 4/5 hours
From 9:00 a.m. to 11 a.m., she has 2 hours, but she only needs 1 4/5 hours to walk, so she will make it to work on time.
Well let's see.

The equation has exactly one solution.
Hope this helps.