What is the answer to this problem ?

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 .

If p(a) = 0.70 and p(b) = 0.20, then a and b are independent events if

Astore sells 4 apples for $3 and 3 oranges for $4 if pete buys 12 apples and 12 oranges how much will it cost