1)how many different ways can a club choose a committee of 4 from 15 members?

2) how many permutations exist of the letters p, q, r, s, and t, taking four at a time?

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )