Keiths Florists has 17 delivery trucks used mainly to delive

Keith’s Florists has 17 delivery trucks, used mainly to deliver flowers and flower arrangements in the Greenville, South Carolina, area. Of these 17 trucks, 7 have brake problems. A sample of 4 trucks is randomly selected. What is the probability that 2 of those tested have defective brakes? (Round your answer to 4 decimal places.)

Solution

frrom 17 trucks we have to select 4 trucks. and out these 4 trucks 2 would have brake problems i.e, these 2 trucks should be any two from defective 7 trucks and the rest two should be any two from the remaining 17-7=10 trucks

so required probability that out of 4 trucks 2 have defective breaks is--

⁷C₂*¹⁰C₂/¹⁷C₄=0.3971 [rounded off to 4 decimal] [answer]