Question

A bag contains:

5 red marbles, 6 blue marbles, 3 green marbles, 4 black
marbles, 2 yellow marbles.
A marble will be drawn from the bag and replaced 200 times.
What is a reasonable prediction for the number of times a
yellow or green marble will be drawn?
( a) 20
b) 30
c) 50
d) 40

Answer 1

c) 50

Explanation:

There are 5 red marbles, 6 blue marbles, 3 green marbles, 4 black

marbles, 2 yellow marbles for a total of 20 marbles

P (yellow or green marble) = number of green or yellow marbles/ total

= 5/20 = 1/4

Take the probability times the number of draws to determine the number of times we would expect to see a green or yellow marble

1/4 * 200 = 50