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# Math riddle watch

1. A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Neither do I know your number.
A: Now I know.

There are four solution for this.What are they ??
-----------
A = 2 B=3
A=9 B=8
(i.e: two solutions - I cannot find 4?)
If A has 2 then B has either 1 or 3 BUT if B had 1 then he would know A's number as they are consecutive: hence A=2, B=3
The same logic applies for 9,8

How are there for solutions and what are they?
2. The answer is 1. The answer in maths problems is always 1. Always.
3. (Original post by jsmith6131)
A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Neither do I know your number.
A: Now I know.

There are four solution for this.What are they ??
-----------
A = 2 B=3
A=9 B=8
(i.e: two solutions - I cannot find 4?)
If A has 2 then B has either 1 or 3 BUT if B had 1 then he would know A's number as they are consecutive: hence A=2, B=3
The same logic applies for 9,8

How are there for solutions and what are they?

A:3, B must have 2 or 4. If 2, B would have knew the answer already, because A said he doesn't know so it can't be 1? A knows B doesn't know so he knows it isn't 2. So it's 3 and 4.

okay one more to go.

Edit: Reading over my answer, I don't think I have been very clear in my reasoning lol.
4. (Original post by amineamine2)
okay one more to go.
+rep.

And apply the same argument to A=8,B=7
5. (Original post by ghostwalker)
+rep.

And apply the same argument to A=8,B=7
Thank you. I had just gone down a reputation level so quite pleased over your rep (as I'm now back to two green boxes)

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