In how many ways can you arrange two white rooks on an empty chess board so that either one could take the other?

To complete your spring schedule, you must add calculus and physics. at 9: 30, there are three calculus sections and two physics sections; while at 11: 30, there are two calculus sections and three physics sections. how many ways can you complete your schedule if your only open periods are 9: 30 and 11: 30?

Which statement accurately explains whether a reflection over the x-axis and a 180° rotation would map figure acb onto itself?

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.