When a family with two adults and three children bought tickets for an amusement park they paid total of 56.50. the next family in line, with four children and one adult, paid 49.50. find the adult and child ticket prices by writing and solving a system of equations.

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.