Mary is driving home from work and needs to make two stops. She first drives at a rate of 25 mph to the supermarket, which is 17
5 miles way from her work, and then she drives to her house, which is 80 miles away from the supermarket, at a rate of 40 mph. What was Mary's average speed for the entire trip?
175 divide by 25 should be 7 then using 80 divide by 40 is 2 7+2=9 then 2 times 40, and 7 times 25, the result is 285 285 divide by 9 get 31.6666......... or 31.7