A bag contains 40 marbles, 4 of which are blue, 10 are red, 25 are green, and 1 is purple. Shawna takes a marble out of the bag, records the color, and returns it to the bag. How many green marbles should she expect after 400 trials?
25
40
100
250

250 green marbles

Step-by-step explanation:

We know that there are 25 green marbles in a bag of 40 marbles. Using this, we can say that the probability of pulling a green marble out of the bag is 25/40, or 5/8. To find out how many green marbles Shawna should expect to pull out of the bag after 400 trials, we have to multiply the amount of trials (400) by the probability of pulling out a green marble (5/8).

400 × 5/8 = (400 × 5)/8 = 2000/8 = 250

Shawna should expect 250 green marbles after 400 trials.

I hope you find this helpful. :)

b) the dogs need to shift their focus to human scent.

no i do not : ( what is it?