Agroup of 45 people attended a ball game. there were twice as many children as adults in the group. set up a system of equations that represents the numbers of adults and children who attended the game and solve the system to find the number of children who were in the group.

The ratio of two numbers is 5 to 4. the sum of the numbers is 99. what number is the greater of the two numbers?

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?

On monday, the water was shut off 3 times for 1/4 hours, 2/3 hours, and 1-3/4 hours, respectively. what was the tireless number of hours the water was off?