Can someone help me with this question please?

Christina can paint 420 square feet in 105 minutes. which unit rate describes the scenario?

Abag contains 3 red marbles, 2 blue marbles, and 2 green marbles. one marble is picked, then another marble. assume that the selections are made with replacement. a) find the probability of picking two red marbles with replacement. b) find the probability of picking a red marble and a blue marble. assume the selections are made without replacement. c) find the probability of picking two red marbles without replacement. d) find the probability of picking a red marble and a blue marble without replacement.

Angles r and s are complementary. the measure of angle r is 31 degrees. which equation can be used to find angle s?