Physics GRE Discussion Forums

If Jimmy can eat a whole apple pie in 24 minutes and Susie can eat a whole apple pie in 36 minutes, how long will it take to eat a single pie if it is shared by Jimmy and Susie?

Ready set go!

-Riley

Use units of s = 6 minutes. Jimmy eats at a rate of 1/4 pie/s, Susie at 1/6 pie/s. So sum them to get 3/12 + 2/12 = 5/12.

Answer is 12/5 s = 12*6/5 minutes = 14.4 minutes.

WhoaNonstop wrote:If Jimmy can eat a whole apple pie in 24 minutes and Susie can eat a whole apple pie in 36 minutes, how long will it take to eat a single pie if it is shared by Jimmy and Susie?

Ready set go!

-Riley

Oh, that's a tough one. Could you rephrase the question in terms of gamma and beta emission half-lives? I do much better with physics than pie.

I wonder if they'd ever put anything about apple pie on the Physics GRE?

-Riley

I believe the answer is 18 min, because Susie threatens to stab Jimmy with the pie knife when he moves to eat part of her half of the pie just after the 12 min mark.

kroner wrote:I believe the answer is 18 min, because Susie threatens to stab Jimmy with the pie knife when he moves to eat part of her half of the pie just after the 12 min mark.

Correct. Maybe we should translate this problem into Beta and Gamma decays, which won't fight over pie.

-Riley

WhoaNonstop wrote:

kroner wrote:I believe the answer is 18 min, because Susie threatens to stab Jimmy with the pie knife when he moves to eat part of her half of the pie just after the 12 min mark.

Correct. Maybe we should translate this problem into Beta and Gamma decays, which won't fight over pie.

-Riley

In which universe do Beta and Gamma decays not fight over pie? Not ours, I can assure you.