Which problem could be solved with the expression 3*(6+4)

a - edward mowed 3 lawns in the morning and 6 lawns in the afternoon. he did this for 4 days. how many lawns did he mow?
b - danielle had 6 dolls. she bought 4 additional dolls. she then went to the thrift store and tripled her collection. how many dolls does she have now?

c - barry ate 3 cookies on monday. he then ate 6 cookies on tuesday. on friday he ate 4 cookies. he follows this pattern for 4 weeks. how many cookies did he eat?

a edward's problem
b danielle's problem
c barry's problem

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.