Question

An engineering example involves inspecting a subset of 19 steel support beams on a bridge for signs of enough wear that they need to be replaced. The truth is that in fact 4 beams need to be replaced. Preliminary testing involves selecting 3 of the 19 beams at random, and if any of the 3 tested beams show sufficient wear, then a more extensive review of all of the beams will be called for. What are the chances that the extensive review will happen? (Hint: it is easier to calculate the complementary probability first, and then subtract it from 1.0.)

Just needed answer for second picture

Answer 1

PCメーリ 12, 1-1) (メッ 3 6us3