An elevator starts on the 100th floor of a building. it descends 4 floors every 10 seconds. at what floor will the elevator be 60 seconds after it starts?

Write a fraction less than 1, which has a denominator of 6 and is greater than 3/4 plz answer !

Find the solution of each of the following.

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?