Five students are seated in a circle. each student has either a red disc or a green disc painted on
her forehead. each student can see the other four discs, but not her own. if a student is wearing a green disc, any state she makes is true; if she is wearing a red disc, any statement she makes is
false.
student 1 says: i see 3 green and 1 red discs
student 2 says: i see 4 red discs
student 3 says: i see 1 green and 3 red discs
students 4 say: it is raining outside
student 5 says: i see 4 green discs
which students have green discs and which students have red discs?

Students 3 and 4 have green discs.  Students 1, 2, and 5 have red discs.

Step-by-step explanation:

If Student 1 is telling the truth, Students 2 and 3 must be lying.  If that were true, Student 1 would see at least 2 red discs, not 1.  So Student 1 is lying, and therefore has a red disc.

Therefore, Student 5 is also lying, and must also have a red disc.

If Student 2 is telling the truth, the other four students must be lying.  That means Student 2 would have a green disc, and the other four would have red discs.  But if that were true, then Student 3 would be telling the truth.  Therefore, Student 2 is lying.

So far, we know Students 1, 2, and 5 are lying.  If Student 3 is telling the truth, then she and Student 4 each have a green disc.  If Student 3 is lying, then all five students would have red discs, which would mean Student 2 was telling the truth.

Therefore, Students 3 and 4 have green discs.  Students 1, 2, and 5 have red discs.

what the question so we can you out

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".