X-15 less than or equal to 9

Car a and car b were in a race .the driver of car b claimed that his car was twice as fast as car a

Aliter of water contains about 3.35 x 10^25 molecules. a certain river discharges about 2.9x 10^8 l of water every second. about how many molecules does the river discharge every minute? write your answer in scientific notation

In triangle abc, w is the centroid and be = 9. find bw. a. 3 b. 6 c. 9 d. 18