How many combinations of 4 students can a teacher choose from 30 students? a. 27,405 b. 120 c. 657,720 d. 810,000

What is the simplified expression for 6(2(y+x))

At oaknoll school, 90 out of 270 students on computers. what percent of students at oak knoll school do not own computers? round the nearest tenth of a percent.

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.