There are twelve
remove two and we have ten
two orange = now we have no orange
two blue = now we have 1 blue so 1/10
two yellow = now we have 2 yellow so 2/10 = 1/5
two green = now we have no green
Just when I got the hang of probability, I get this question and I'm so lost. Can anyone help?
Molly has a jar containing 4 yellow, 3 blue, 3 green, and two orange marbles.
Molly returned all marbles to the jar. She then removed some marbles of one color from the jar. The removal changed the probability of drawing that color marble in 1 turn to equal 1/5. Name the color and number of marbles Molly removed.
A) 2 orange
B) 2 blue
C) 2 yellow
D) 2 green
3 answers
Here's an example of what the question is asking for:
If Molly removed 2 orange marbles, the probability of drawing an orange marble from the remaining batch is
P(Orange) = (2-2)/(4+3+3+0) = 0/10 = 0
and that does not equal 1/5, so she did not remove 2 orange marbles.
Since in all cases, two marbles have been removed, leaving 10 marbles, and
P(colour?)=1/5
So the remaining coloured marble is
10*(1/5)=2
What coloured marble will have two left after removing 2 of that colour?
If Molly removed 2 orange marbles, the probability of drawing an orange marble from the remaining batch is
P(Orange) = (2-2)/(4+3+3+0) = 0/10 = 0
and that does not equal 1/5, so she did not remove 2 orange marbles.
Since in all cases, two marbles have been removed, leaving 10 marbles, and
P(colour?)=1/5
So the remaining coloured marble is
10*(1/5)=2
What coloured marble will have two left after removing 2 of that colour?
Thank you!!!!!! I get it now.
2 answers