The probability that an electronic device produced by a company does not function properly is equal to 0.1. If 10 devices are bought, then the probability, to the nearest thousandth, that 7 devices function properly is

A. 0.057

B. 0.478

C. 0.001

D. 0

The answer is A, 0.057. This one you can solve using logic. D is to low, C is also to low. That leaves A and B. If your rounding to the nearest thousandth C and D don't make to much sense. Looking at it, considering its 7 devices, A makes the most sense. I'll write the math up here later if you want.