Fun little problem (1 Viewer)

[SunnyScience]

Sabrina gave Samantha as many dollars as Samantha started out with. Samantha then gave Sabrina back as much as Sabrina had left. Sabrina then gave Samantha as back as many dollars as Samantha had left, which left Sabrina broke and gave Samantha a total of $80.00. How much did Sabrina and Samantha have at the beginning of their exchange?

 

[Carrotsticks]

Just tried it quickly and I got:

Sabrina = 32

Samantha = 24

Turns out I can't even solve a system of just 2 linear equations properly haha.

 

[D94]

I got Sabrina = $ 50 and Samantha = $30.

 

[Parvee]

The wording is annoying -.-
I got $50 and $40

 

[bleakarcher]

Sabrina-50
Samantha-30

 

[AAEldar]

Doesn't the question imply that the total money they start with has to add up to $80? Or am I not reading it correctly...

 

[D94]

Doesn't the question imply that the total money they start with has to add up to $80? Or am I not reading it correctly...

Yes, exactly what I thought. No money is taken out of the set nor is any being put in. Two values which don't add up to 80 cannot be in the set.

 

[bleakarcher]

Sabrina Samantha
x y
x-y 2y
2(x-y) 2y-(x-y)
2(x-y)-[2y-(x-y)] 2[2y-(x-y)]

2(x-y)-[2y-(x-y)]=0
2[2y-(x-y)]=80

Solve for x and y.

 

[bleakarcher]

^damnit, I tried making a table but it didnt work. The ones on the left represent the amount sabrina has at the 1st, 2nd, 3rd exchange and the ones on the right representing the amount samantha has. x and y is how much they had initially.

 

[deterministic]

just work backwards, screw using equations and algebra

 

[Demento1]

Sabrina Samantha
x y
x-y 2y
2(x-y) 2y-(x-y)
2(x-y)-[2y-(x-y)] 2[2y-(x-y)]

2(x-y)-[2y-(x-y)]=0
2[2y-(x-y)]=80

Solve for x and y.

This is what I got when I tried solving the simultaneous equations:

Call that (1)
Call that (2)

From (1) I can't bother typing all the working out up but I got:


Sub into (2) And I eventually got:


Sub Back into (1)

And I eventually got y = 30 and x = 50.

 

[bleakarcher]

just work backwards, screw using equations and algebra

that actually requires more thinking LOL.

 

[Demento1]

The question is annoying because of the way it's worded

 

[deswa1]

that actually requires more thinking LOL.

Not really. I just did it in 1 minute like so (working backwards):
Sabrina, Samantha
$0, $80
$40, $40
$20, $60
$30, $50

 

[bleakarcher]

There are some errors in the sentences, it's not too bad though.

 

[bleakarcher]

Not really. I just did it in 1 minute like so (working backwards):
Sabrina, Samantha
$0, $80
$40, $40
$20, $60
$30, $50

ah yeh true, its pretty damn simple that way too lol.

 

[SunnyScience]

Sorry guys, I actually just copied and pasted this off a riddle site so the wording is meant to be somewhat confusing.

The answer is 30 and 50 though - so good work to the ones who got it

Sent from my LG-P990 using Tapatalk

 

[Demento1]

ah yeh true, its pretty damn simple that way too lol.

Deswa1 makes mathematics look easy.

 

[bleakarcher]

I knew about the 'simpler' way (the way deswa just did it) I just couldn't be bothered thinking backwards lol. To be honest, using algebra would be the dopie way to do it.