jane takes 4 hours to do a job that Alice can do in 3 hours. if jane works 1/2 hour before Alice joins her, how long will it take the two of them to finish the job

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{ {