A principal orders t-shirts and wants to check some of them to make sure they were printed properly, she randomly selects 7 of the 10 boxes and checks 20 in one box and 40 in others. What type of sampling is this?

Awoman has 14 different shirts: 10 white shirts and 4 red shirts. if she randomly chooses 2 shirts to take with her on vacation, then what is the probability that she will choose two white shirts? show your answer in fraction and percent, round to the nearest whole percent.