Binomial Prob. Question! (1 Viewer)

[kcqn93]

This is from the 3unit fitz Exercise 29(b) q27

27) A factory has 7 machines, 4 of model A which are in use, on average, 80% of the time and 3 of model B which are in use, on the average, 60% of the time. If a foreman walks into the factory at a randomly selected time, what is the probability that

i) he will find 2 machines of model A and 1 of model B in use

ii) he finds 2 machines in use

answers: i) 0.04422 ii) 0.0179

thanks in advance

 

[~caramello~]

Do model A and model B seperately.

For example,
the equation for model A is (W+N)^4, where w is working at 0.8 and n is not working at 0.2

Similarly for model B is (W+N)^3, where w = 0.6 and n=0.4

And remember to times the A and B since it says AND.

Hope that helps

 

[kcqn93]

Do model A and model B seperately.

For example,
the equation for model A is (W+N)^4, where w is working at 0.8 and n is not working at 0.2

Similarly for model B is (W+N)^3, where w = 0.6 and n=0.4

And remember to times the A and B since it says AND.

Hope that helps

THANKS!! i got it