727x10by the power of 1

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?

Two farmers pay a total rent of $140 for a pasture. the first farmer placed $4 oxen in the pasture, and the second farmer placed $30 sheep in the pasture. the farmers split the rent based on the proportion of the pasture eaten by their own animals that month. how much should the first farmer pay, if 1 ox eats as much as 10 sheep in a month?

Abag contains 5 red marbles , 6 blue marbles and 4 green marbles. susie selects a marble and returns it to the bag before selecting another marble. if susie selects a red marble 6 out of 20 times, what is the experimental probability that the next marble she selects will be a red marble ?