About 23% of people who get their eyes examined are found to have a detached retina (the retina is piled away from the tissue at the back of the eye.) what is the probability of an ophthalmologist examining seven people until he finds the first patient who has a detached retina?

a. (0.23)^7
b. (0.23)^6(0.77)^1
c. (0.77)^7
d. (0.77)^6(0.23)^1
e. 1-(0.23)^6

Ahigh definition tv cost $800 with a down payment of 2/5 of the cost. how much is left to pay, in dollars after the down payment has been made?

Sh what is the value of x? ox= 2.25 x = 11.25 ox= x = 22 1 (2x + 10) seo - (6x + 1) -- nie

Suppose we have a set of small wooden blocks showing the 26 letters of the english alphabet, one letter per block. (think of scrabble tiles.) our set includes 10 copies of each letter. we place them into a bag and draw out one block at a time. (a) if we line up the letters on a rack as we draw them, how different ways coukl we fill a rack of 5 letters? (b) now suppose we just toss our chosen blocks into a pile, and whenever we draw a letter we already have, we put it back in the bag and draw again. how many different piles of 5 blocks could result? possible? piles will contain at least one repeated letter? (c) if we draw out 5 blocks wit hout looking at them, how many different piles are (d) if we draw out 5 blocks without looking at them, how many of the possible 2. (4) consider the following formula. 12 give two different proofs, one using the factorial formulas and the other combina torial.