Question

a box contains 20 red marbles and 30 blue marbles.A second box contains 10 white marbles and 40 black marbles.If you choose one marble from each box without looking, what is the probability that you get a blue marble and a black marble?

Answer 1

I think it's 12/25.
The first box has 20 red and 30 blue, which equals 50 marbles total.
The probability of pulling a blue marble out is 30/50, or 3/5.
The second box has 10 white and 40 black, which, again, equals 50 marbles total. The probability of pulling a black marble out is 40/50, or 4/5.
3/5*4/5=12/25=4/5.
Hope this helps =)

Answer 2

The probability of you picking out a blue marble would be 30/50 and the probability of you picking out a black marble would be 40/50.
To find out the probability of both you just add them together so 70/100.
I hope this helps.