Eric wants to send a package to his mother. If he chooses UPS, the fixed express fee is 10 dollars and each kilogram costs 2 dollars. For Fedex, the fixed fee is 20 dollars and each kilogram costs only 1 dollar. If the total costs of the two options are the same, how many kilogram of package does Ericsend? Write a system of equations in order to solve this problem.

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.