The sum of two positive integers, and y, is not more than 40. the difference of the two integers is at least 20
chaneece chooses x as the larger number and uses the inequalities y s 40 - x and y sx-20 to determine the
possible solutions she determines that x must be between 0 and 10 and y must be between 20 and 40. determine if
chaneece found the correct solution. if not, state the correct solution
yes, chaneece found the correct solution
no chaneece mixed up the variables. the correct solution is that must be between 20 and 40 and y must be
between 0 and 10
no chaneece should not have restricted the solution to quadrant 1. the correct solution is that x can be all real
numbers and y must be less than 10
no chaneece looked at the wrong area of the shaded graph. the correct solution is that must be between 0
and 30 and y must be between 0 and 40

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.