math fun with your vcr

[morkinva]

Okay, suppose you need to record a program that's 2 hrs 37 minutes long, using a 2 hr tape. You have 2 speeds to choose from, SP which would use up the full tape in 2 hrs time, and EP which if used exclusively would allow 6 hrs of recording. Speed SP uses 3 times as much tape per minute as speed EP.

At what point in time would you need to switch from SP to EP in order to exactly fill the tape for the 2hr 37min program?

 

[CoBRaXT]

1 hour, 37 minutes, 40 seconds

 

[MartyMcFly3]

Originally posted by: morkinva

At what point in time would you need to switch from SP to EP in order to exactly fill the tape for the 2hr 37min program?

Probably the same point in time where you realize that itd be easier just to tape the whole damn thing on EP

 

[bootymac]

Fsck recording it, I'd just watch it

 

[morkinva]

Originally posted by: CoBRaXT
1 hour, 37 minutes, 40 seconds

close

lol Mcfly 😎

 

[ArmenK]

x - 3(2-x) = 2 + 37/60
4-2x = 37/60
(4-37/60)/2=x
x= 1.6917

1 hour, 41 mins, 30 seconds

 

[morkinva]

Originally posted by: ArmenK
1 hour, 41 mins, 30 seconds

Winnah!!


the 2 hr tape, for our purposes, is made up of x minutes plus (120-x) minutes. But at the point you switch from SP to EP, the remaining time is 3(120-x) minutes.

157 = 360-3x+x
203 = 2x
x = 101.5

 

[DaviDaVinci]

it's 3 am man. why are you thinking at such hours?

 

[Heisenberg]

Originally posted by: DaviDaVinci
it's 3 am man. why are you thinking at such hours?

It's basic algebra. That's not thinking.

 

[rival]

Originally posted by: Heisenberg

Originally posted by: DaviDaVinci
it's 3 am man. why are you thinking at such hours?

It's basic algebra. That's not thinking.

i take it you missed the 3am part...