[MOVED] 8 discs question (probability)

[dod]

Can someone help with this one please - What I would have said for first one is 1/8 x 1/8 = 1/64but the "in that order" part of the question is throwing me off now, I can't figure out how the probability would change if it does change at all???

And help with others please, thank you

 

[HallsofIvy]

Yes, there are 8 disks in the bag, one of which is "2", so the probability of the first disk being "2" is 1/8 and, since we put the disk back the probability of the second disk being "4" is also 1/8. The probability of getting "2" and "4" in that order is (1/8)(1/8)= 1/64.

If it had NOT said "in that order" then you would have to consider "first 4 and then 2". The probability of that is, of course, also 1/64 so the probability of "2" and "4" in either order (2, 4 or 4, 2) would be 1/64+ 1/64= 1/32.

Since you got that right, have a try at the others and let us know what you got. None of the others say "in that order" but, of course, with "5 each time" order does not matter.