In a group of 30 children, 80%can’t swim how many children can’t swim

Show algebraically that f and g are inverse functions f(x)=x^2/-6; g(x)=square root of 2x+12

How do i do this activity, is appreciated

Suppose i pick a jelly bean at random from a box containing one red and eleven blue ones. i record the color and put the jelly bean back in the box. if i do this three times, what is the probability of getting a blue jelly bean each time? (round your answer to three decimal places.)