I need help solving question 2

2)A laboratory contains ten electronic microscopes, of which two are defective. Four are to be tested. All microscopes are equally likely to be chosen. A sample of four microscopes can have zero, one, or two defective ones, with the probabilities given. What is the expected number of defective microscopes in the sample? Number of O 1 2 defections probability 8 2 WIH 15 15