Show that if the fair chance odds against an event are rfair to 1,then in a bet at payoff odds of rpay to 1 the house percentage is rfair-rpay/rfair + 1 *100%

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.)