What does E=MC2 mean? Thanks.

There are 45 questions on your math exam. you answered 810 of them correctly. how many questions did you answer correctly?

240 seventh graders and two-thirds of the students participate in after-school activities how many students participate in after-school activities

Traffic on saturday, it took ms. torres 24 minutes to drive 20 miles from her home to her office. during friday's rush hour, it took 75 minutes to drive the same distance. a. what was ms. torres's average speed in miles per hour on saturday? b. what was her average speed in miles per hour on friday?