Suppose that a box contains 7 cameras and that 4 of them are defective. A sample of 2 cameras is selected at random. Define the random variable X as the number of defective cameras in the sample. Write the probability of X. What is the expected value of X?

The median segment divides the triangle into 2 isosceles triangles and everything else is trivial.|ad|=|bc|2=|bd|soδadb  is isosceles with∠dab=∠dbasimilarlyδadc  is isosceles with  ∠dac=∠dca∠cab=∠cad+∠bad=∠acb+∠abctherefore∠cab  is a right angleandbc  is the hypotenuse of a right-angled triangle.hope this