SAT Problem

[troublemaker676]

How would ypu go about solving a problem like this?

If rstv=1 and stuv=0, which of the following must be true?

(a) r<1

(b) s<1

(c) t>1/2

(d) u=0

(e) v=0

 

[Unco]

From rstv=1, what must each of these variables not be equal to?

 

[Denis]

Not sure what yo mean, Unco; could be 1/2 * 2 * 1/4 * 4

"If rstv=1 and stuv=0, which of the following must be true?"
u = 0 is the only true one, since stv is part of both.

 

[Unco]

None of those four can be zero, Denis.

 

[Denis]

None of those four can be zero, Denis.

Huh? Ok, but so what? Are we looking at same problem?

If rstv=1 and stuv=0, which of the following must be true?
(a) r<1
(b) s<1
(c) t>1/2
(d) u=0
(e) v=0

(d) u=0 must be true (since s,t,v are not equal 0)

 

[Unco]

If r, s, t and v are not zero, then for stuv=0, u must be zero. I'm not sure what your problem is.

 

[troublemaker676]

After looking over the problem again and reading you guy's responses it has to be (d) u=0, that is the only one you know for sure has to be true.

 

[Denis]

If r, s, t and v are not zero, then for stuv=0, u must be zero. I'm not sure what your problem is.

That's EXACTLY what I'm saying, Unco!

rstv=1 and stuv=0; so:

none of r,s,t,v can equal zero [1]

s,t,u,v: since none of s,t,v can equal 0 [1], then u MUST equal 0,
plus is the ONLY one of the choices that is a MUST.

Perhaps I was unclear on my 1st post; I was trying to indicate that r,s,t,v did not
necessarily all equal 1, which is what I thought you meant by your post:
"From rstv=1, what must each of these variables not be equal to?";
I misread that as:
From rstv=1, what must each of these variables be equal to?