You are a camp director, and three people who forgot to bring flash lights want to go for a hike at night. Each of these people will need a working flashlight. You have many flashlights in your storage area, but because of indifferent upkeep, many of the flashlights do not work. For each flashlight the probability it works is 0.75. What is the probability the camp director will need to test exactly 7 flashlights to find three working flashlights?