A box contains 3 defective batteries and 7 good ones. You reach in and pull out three batteries. What is the expected number of defective batteries?

The expected number of defective batteries to be pulled out is 0.9, which rounded to the nearest integer gives a total of 1, that is, 1 of the 3 batteries is expected to be defective.

Step-by-step explanation:

Given that a box contains 3 defective batteries and 7 good ones, and I reach in and pull out three batteries, to determine what is the expected number of defective batteries, the following calculation must be performed:

3 + 7 = 100

3 = X

10 = 100

3 = X

3 x 100/10 = X

300/10 = X

30 = X

3 x 3/10 = X

0.9 = X

Therefore, the expected number of defective batteries to be pulled out is 0.9, which rounded to the nearest integer gives a total of 1, that is, 1 of the 3 batteries is expected to be defective.

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step-by-step explanation:

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b - exponent

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