0) The participants are isolated. 1) With equal probability, each participant is independently given a black or a white hat. They do not see their own hat colour.
2) Each participant sees a photograph of everyone else wearing their hats. (No sneaky signalling permitted)
3) Each participant guesses the colour of their own hat.
4) The participants collectively win if more than half of them guess correctly.

How should the participants play to win?

b

step-by-step explanation:

b

a

step-by-step explanation:

given the 2 equations

- x + y = - 2 → (1)

2x - 3y = 4 → (2)

multiplying (1) by 2 and adding to (2) will eliminate the x- term

- 2x + 2y = - 4 → (3)

add (2) and (3) term by term

(2x - 2x) + (- 3y + 2y) = (4 - 4), simplifying gives

- y = 0 ⇒ y = 0

substitute y = 0 in either of the 2 equations for corresponding value of x

substituting in (2) gives

2x = 4 ( divide both sides by 2 )

x = 2

solution is (2, 0 ) → a