Describe how batteries provide electrical charges

Jiovanni is looking in to two different companies that offer study guides for math exams.test prep 101 charges a $5 flat fee and an additional $0.25 per problem.math charges a $2 flat fee and an additional $0.50 per problem.how many prablems would make the costs of the two companies be equal? varibles: equations/eniqualities{ {

Ineed with numbers 8,9and10 answer fast i have 10 minutes

Kari plans to sample 20 people of a population that contains 100 students. she wants to determine how many people wake up before 6 a.m. which sample is the most random?