SOLUTION: Kathryn left the mall and traveled toward the town hall. Three hours later Jessica left traveling 30 mph faster in an effort to catch up to her. After two hours Jessica finally cau

Algebra ->  Human-and-algebraic-language -> SOLUTION: Kathryn left the mall and traveled toward the town hall. Three hours later Jessica left traveling 30 mph faster in an effort to catch up to her. After two hours Jessica finally cau      Log On


   

Question 1121130: Kathryn left the mall and traveled toward the town hall. Three hours later Jessica left traveling 30 mph faster in an effort to catch up to her. After two hours Jessica finally caught up. What was Kathryn's average speed?
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


Jessica covered in 2 hours what Kathryn covered in 5 hours, so Jessica's speed was 5/2 of Kathryn's speed.

Formal algebra, or a bit of logical reasoning and mental arithmetic, tells us that, since 5/2 of Kathryn's speed is 30mph faster than Kathryn's speed, the two speeds are 20mph and 50mph.

So Kathryn's average speed was 20mph.

Comment.... 5 hours at 20mph = 100 miles -- that's a rather large town.......