Question

Suppose electric power is supplied from two independent sources which work with probabilities 0.4 and 0.5. What is the probability that at least one of the sources will work?

1) 0.1
2) 0.4
3) 0.5
4) 0.9

Answer 1

The probability that at least one of the sources will work is 0.7.

Step-by-step explanation:

To find the probability that at least one of the sources will work, we can calculate the probability that both sources won't work and subtract it from 1. The probability that the first source won't work is 1 minus the probability that it will work, so it is 1 - 0.4 = 0.6. Similarly, the probability that the second source won't work is 1 - 0.5 = 0.5. Since the two sources are independent, the probability that both won't work is obtained by multiplying their individual probabilities, 0.6 * 0.5 = 0.3.

Therefore, the probability that at least one of the sources will work is 1 - 0.3 = 0.7.