1.Graphite is made up of layers of graphene. Each layer of graphene is about 200 ×10-12 meters thick. How many layers of graphene are there in a piece of graphite that is 1.6 10-3 meters thick? Express your answer in scientific notation.

Kevin has just finished paying off his loan. he was assessed a service charge of $422. he paid off the principal and the interest by making weekly payments of $36.13 for four years. if the principal was $7,150, how much did kevin pay in finance charges, to the nearest dollar? a. $498 b. $365 c. $422 d. $787

Darian wants to build a regulation size pool table that is 9 feet in length. he plans he ordered are 18 by 36 inches. what is the scale factor of the dilation he must use to build a regulation pool table

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?