Sohan rolled a number cube 90 times. The outcome of “6” occurred 18 times. What is the theoretical probability of rolling a 6?

When using the linear combination metho e linear combination method to solve a system of linear equations, the four options are:

The two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16

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?