The ratio of the number of people who own a smartphone to the number of people who own a flip phone is 4:3. If 500 people own a smartphone,
how many people own a flip phone?

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