We have been given that L'shanda can choose between 3 sweaters and 4 skirts.
We need to figure out the number of ways in which L'shanda can pick 1 sweater and 1 skirt out of the available items.
We need to use combinations here. First of all, we will figure out the number of ways of choosing 1 sweater out of 3 available sweaters. And then we will determine the number of ways of choosing 1 skirt out of 4 available skirts.
Number of ways of choosing 1 sweater =

Number of ways of choosing 1 skirt =

Therefore, total number of ways to select 1 sweater and 1 skirt are
