INSANE

[dayse]

I AM GOING INSANE. TRULY TRULY. JUST CRZY. OMG.

Okay, so normally I'm pretty good with the puzzles/riddles, and I dunno, guys, I DUNNO, maybe it's because it's late and I haven't had enough sleep but I just can't figure this one out and I swear to God I'm just - I'm going to lose it. You are all very smart, SO PLZ - PLZ HALP:

While walking through a market on vacation, you notice a small stand selling cameras. A camera-and-case set is selling for $310. The seller tells you that the camera costs $300 more than the case itself and that the case costs the price of the set minus the cost of the camera.

You decide you'd rather wait on buying a camera and opt to just by the case alone. You hand the seller a $100 bill and see his eyes light up. Think fast now! How much change should you be getting back?

The answer is an actual dollar amount, so it's none of that 'oh they don't take $100 dollar bills' or something like that. And omg, I just know it's going to be something so painfully obvious I'll feel like even more of a dumbass afterwards.

Help me! Help me before I lose my mind [cries]

[hobbles off to bed]

Comments

[veracity]

I would love to help you, truly, but I'm math retarded.

[jcjoeyfreak.livejournal.com]

ELEVENTY MILLION!

[sorchar.livejournal.com]

$95

[wenelda.livejournal.com]

The seller tells you that the camera costs $300 more than the case itself and that the case costs the price of the set minus the cost of the camera.

so...shouldn't it be 10? which would mean you'd get 90 dollars back?

i hate word problems.

[malnpudl.livejournal.com]

Huh? How is the answer not $90?

Camera + Case = $310
Camera = $300 + Case
Case = $310 - $300 = $10

$100 bill - $10 (case) = $90 change

Seems very straightforward to me.

[likeasunburn.livejournal.com]

Another vote for $90 here.

[iterationzero.livejournal.com]

let x = the cost of the camera
let y = the cost of the case

x + y = 310
x = 300 + y
y = 310 - x

you can substitute the values for x or y from one of the last two equations in to the first one. let's do the x value...

(300 + y) + y = 310
300 + 2y = 310
2y = 10
y = 5

so if he doesn't give you back $95, hit him.

[jennytsk.livejournal.com]

I'm of the Camera Case Costs $5, You Get $95 back school.

Camera Case = X
Camera = X + 300

2x + 300 = 310
2x=10
x=5

Camera case costs $5
You get $95 back.

The key phrase is "camera costs $300 more than the case itself", not "camera costs $300"

The camera costs $305.

MATH GEEKS UNITE!

[shayheyred.livejournal.com]

I'd go to B&H and buy the whole set for $50.