How many distinct three-digit numbers can be made from $1,2,2,3,4$ and $5,$ using each at most once?

From three sets of twins and four unrelated girls, find how many selections of five people can be made if exactly:

two sets of twins must be included

From three sets of twins and four unrelated girls, find how many selections of five people can be made if exactly:

one set of twins must be included.

Two children are selected at random from a group of six boys and four girls. Use combinations to find the probability of selecting:

two boys

Two children are selected at random from a group of six boys and four girls. Use combinations to find the probability of selecting:

two girls

Two children are selected at random from a group of six boys and four girls. Use combinations to find the probability of selecting:

one boy and one girl.

Three chocolates are selected at random from a box containing $10$ milk chocolates and $15$ dark chocolates. Find the probability of selecting exactly:

two dark chocolates

Three chocolates are selected at random from a box containing $10$ milk chocolates and $15$ dark chocolates. Find the probability of selecting exactly:

two milk chocolates

Three chocolates are selected at random from a box containing $10$ milk chocolates and $15$ dark chocolates. Find the probability of selecting exactly:

two dark chocloates or two milk chocolates