10. A hobby pack of baseball cards contain 9 cards and a jumbo pack contains 35 cards. Ethan bought 7 packs for a total of 141 cards. How
many packs of hobby and jumbo did Ethan buy?

Farnesene is a sesquiterpene. how many different isomers arising from double-bond isomerizations are possible? g

The diameter of a circular chip is doubled to use in a new board game. the area of the new chip will be

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.