This is the beginning of all probability problems.
Memorize it:
Probability =
(number of ways to be successful)
divided by
(total number of possibilities) .
What's the total number of possible ways to pull out one sweater ?
. . . . . There are 5 sweaters in the bag, so 5 total possibilities.
How many ways are there to pull out a medium sweater ?
. . . . . There are 2 medium sweaters in the bag.
. . . . . Lydia might pull out this one, or she might pull out that one.
. . . . . There are 2 ways to pull out a medium sweater.
Probability = 2 / 5 = 40% .
Now you've posted enough of these, and gotten answers with
explanations, so you should be able to do them on your own now.
