If I’m 100 mile way for some place and I start driving towards it at 100 Miles an hour, BUT when I'm 99 miles away, I slow down to 99 MPH, and when I’m 98 miles away, I slow down still to 98 MPH, and so forth, until I’m one mile away and I slow down to 1 mph.
How long will it take me to reach my destination?
2006-06-22 13:14:43 · 12 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
d = rt
t = d/r
d = 100 = 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + ... + 1
(add 1 100 times)
the rate decreases, so
t = d/r
t = 1/100 + 1/99 + 1/98 + 1/97 + ... + 1/1 hours
^_^
2006-06-23 00:52:01 · answer #1 · answered by kevin! 5 · 2⤊ 1⤋
The first answer was correct. Five hours Eleven minutes and Fifteen seconds (rounded to the nearest second.)
Think about the other answers (2 hours). It will take One hour to finish the last mile at 1 mph. Then add 30 minutes for the mile before that, 20 minutes for the mile before that, 15 minutes for the mile before that, then 12 minutes, then 10 minutes. So just the last six miles takes you Two hours and Twenty-seven minutes.
BTW, your average speed is actually just under 20 mph.
2006-06-22 13:36:23 · answer #2 · answered by ewetaunt 3 · 0⤊ 0⤋
Bequal is right. It can't be 2 hours. Use your common sense. On the last mile, it would take 1 hour alone. On the second mile, it would take 30 minutes. On the third mile, it would take 20 minutes. On the fourth mile, it would take 15 minutes. Quick easy math... so far we are at 2 hours and 5 minutes and we are still not done with the problem. Now, follow the formula given and you will be OK.
(PhD Mathematics)
2006-06-22 14:10:23 · answer #3 · answered by Anonymous · 0⤊ 0⤋
This should be a simple summation series...
Total Time (in hours) = (1 + 1/2 + 1/3 + 1/4 + 1/5 + etc.....+ 1/99 + 1/100)
2006-06-22 13:29:22 · answer #4 · answered by puzzledwithexcel 2 · 0⤊ 0⤋
Sure, it would take 5.187 hours if you drove straight through. You probably don't have to stop for gas -- but driving that long, you would have to add some time for bathroom breaks and -- perhaps -- a nice lunch.
You'd also have to add some time because the cops would pull you over for speeding during the first part of the trip and for going too slowly during the last part.
Al together, I'm thinking three or four days.
2006-06-22 16:17:45 · answer #5 · answered by Ranto 7 · 0⤊ 0⤋
About 5 hrs, 11 mins, 14.56 seconds. Your first mile takes 1/100 of an hour. Your second mile takes 1/99 of an hour, et cetera...
2006-06-22 13:47:12 · answer #6 · answered by Carol J 2 · 0⤊ 0⤋
1+1/2+1/3+1/4+...1/100 hours.
I did some formulating in excel and it comes to: 5.18737751763962 hours.
2006-06-22 13:17:48 · answer #7 · answered by bequalming 5 · 0⤊ 0⤋
you're average speed is 50 mph so it would take 2 hours
2006-06-22 13:20:00 · answer #8 · answered by Pancho 1 · 0⤊ 0⤋
it would take you about 2 hours
2006-06-22 13:21:07 · answer #9 · answered by monkyodoom 2 · 0⤊ 0⤋
about 1.98 hours or approximately, 2 hours...
2006-06-22 13:25:08 · answer #10 · answered by meow 3 · 0⤊ 0⤋