QR problem?

[failedmagician]

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A thief leaves at 11 AM traveling 45 mph. At 11:20 a cop goes after him at 50 mph. What time will the cop catch the thief?

I can't figure this out.

 

[YourDentition]

I think the answer is 18min. This being the reasoning:

The thief is running at 45m/h or 45mil in 60 min. --> so, 15 miles in 20 mins (which is the lag time).
In order for the police to overcome that distance and running at 50mil in 60 min.
it will take him .3hours or 18 mins

I hope i'm right (if i'm) then hope this helps.

 

[ttran9229]

I think the answer is 18min. This being the reasoning:

The thief is running at 45m/h or 45mil in 60 min. --> so, 15 miles in 20 mins (which is the lag time).
In order for the police to overcome that distance and running at 50mil in 60 min.
it will take him .3hours or 18 mins

I hope i'm right (if i'm) then hope this helps.

Your answer is correct if the thief stopped travelling at 45mph. If he continued at that pace, it will take the cop 3 hrs to offset the 15 mile deficit.

 

[theconfused1]

A thief leaves at 11 AM traveling 45 mph. At 11:20 a cop goes after him at 50 mph. What time will the cop catch the thief?

I can't figure this out.

So by 11:20, the thief has traveled 15 miles. (45 X 20/60)
However the thief is still traveling at the same speed as the cop starts chasing. So the difference here is (50-45=5 mph). In order to travel 15 miles at the speed of 5 mph, 3 hours is needed.
So it would be 2:20 pm
correct me if I'm wrong

 

[YourDentition]

you are right...i completely forgot about the thief at that point...(yes, so now the differential speed is 5m/h ...n time that'll take would be 3 hours)

 

[failedmagician]

So by 11:20, the thief has traveled 15 miles. (45 X 20/60)
However the thief is still traveling at the same speed as the cop starts chasing. So the difference here is (50-45=5 mph). In order to travel 15 miles at the speed of 5 mph, 3 hours is needed.
So it would be 2:20 pm
correct me if I'm wrong

Thank you to everyone. You got it right, it's 2:20pm

Okay so it's 15 miles at the speed of difference. Wow. That's not how I was thinking of it at all..wow..

 

[pbure9]

yea i believe 2:20 is right.

their Distances have to be equal.
so the theif is traveling at 45t while the cop is traveling at 50(t-1/3)
1/3 since he leaves 20 minutes after the theif. If you work that out, you should get 3 hours and 20 min for t, which will give you 2:20pm.

Just another way to do it. Cool problem