4/5k = 12 what is the answer because I am a not smart 6th grader

An energy drink company claims that its product increases students' memory levels. to support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. the missing component in this study is a .

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?