During a certain week, a post office sold rs.280 worth of 14-paisas stamps. how many of these stamps did they sell?

Select a graph that have an equation with a < 0

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Suppose you just purchased a digital music player and have put 8 tracks on it. after listening to them you decide that you like 4 of the songs. with the random feature on your player, each of the 8 songs is played once in random order. find the probability that among the first two songs played (a) you like both of them. would this be unusual? (b) you like neither of them. (c) you like exactly one of them. (d) redo () if a song can be replayed before all 8 songs are played.