A mother tracks the duration of her baby's three daily naps for a few weeks. The mean time, in minutes, and the standard deviation, SD, for each nap are recorded in the table below.

1st Nap 2nd Nap 3rd Nap
Mean = 83
SD = 9 Mean = 52
SD = 6 Mean = 39
SD = 11

How do you use the elimination method for this question? explain, because i really want to understand!

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?

The price of a dozen eggs was $1.63. suppose the price increases m dollars per dozen and then the price decreases $0.12 per dozen. which expression represents the current price of eggs after the two price changes?