The ratio of the number of participants in the spinning classes to the number of participants in the Zumba class is 10 to 8. There are 120 members in the Zumba classes. How many members are in the spinning classes?

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?