In a shop there are 20 customers, 10 of whom will make a purchase. if three customers are selected, one at a time, at random, what is the probability that all will make a purchase?

What is sin 7x/4 ? i need on this urgent trig

Sue's average score for three bowling games was 162. in the second game, sue scored 10 less than in the first game. in the third game, she scored 13 less than in the second game. what was her score in the first game?

What is the value of n in the equation -1/2(2n+4)+6=-9+4(2n+1)