The game show contestant spins a spinner with the letters E, W, Y, l and Z on it, then either an easy or a hard question is picked randomly for her. What is the probability that the spinner will stop on either Y or W and she is given an easy question?

  1/5

Step-by-step explanation:

We assume the events are independent, so the probability of the joint event is the product of the probabilities of the individual events.

  P(Y or W) = 2 letters of 5 = 2/5

  P(easy) = 1 of 2 kinds = 1/2

The product of these is ...

  P((Y or W) and (easy)) = (2/5)(1/2) = 1/5

In both cases, we have to assume that each of the possible outcomes is equally likely.

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this