How do you solve this problem. there are approximately 2.1 million deaths per year in country a. express this quantity as deaths per minute.

Well... we know that... there are 365 days in a year, unless is a leap-year, but we'll use 365 anyway

and each day has 24hrs, each hr has 60 minutes

so. let us use those ratios



so.. multiply and simplify, cancelling out any like-units atop and bottom

notice, all we do, is use the ratios, in a way, that if we need one unit to be changed, we flip the ratio

for example, to toss away "year" unit, since in the first fraction is at the bottom, then we put it on the top on the ratio, year/year  = 1, effectively cancelling the unit