Johnny leaves Memphis to visit his cousin, Anne Hoffman, who lives in the town of Hornsby, TN, 80 miles away. He travels at an average speed of 50 mph. One-half hour later, Anne leaves to visit Johnny, traveling at an average speed of 60 mph. How long after Anne leaves will it be before they meet?
2007-01-18 06:02:51 · 3 answers · asked by World Expert 1 in Education & Reference ➔ Homework Help
for the first .5 hours, J has travelled 50*.5 = 25 miles.
Distance between J and A when A starts = 80-25 = 55miles.
Suppose they meet T hours after A starts
50*T + 60*T = 55
110*T = 55
T = 0.5 hours
2007-01-18 06:52:50 · answer #1 · answered by mandeep 3 · 1⤊ 0⤋
The original distance is 80 miles.
Johnny has traveled 25 miles (50 * 1/2 hour) so the remaining distance is 55 miles.
Johnny and Anne are traveling towards each other at a total of 110mph. So Anne and Johnny will meet in 55/110 hours or 1/2 hour after Anne leaves.
2007-01-18 06:09:59 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Johnny leaves half an hour before Anne does, so he'll have already traveled 25 miles (50mph * ½ hr). Then Anne leaves, going 60 mph. Another half hour later, she's gone 30 miles while Johnny has gone another 25. 25+25 = 50, and 50 + 30 = 80
Answer: 30 minutes after Anne left (60 minutes total)
2007-01-18 06:11:13 · answer #3 · answered by thweekus 1 · 0⤊ 0⤋