Find the diagonal distance from one corner of a square classroom floor to the other corner of the classroom floor if the length of the floor is 31 feet.

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.