Answer:
The probability that the first two electric toothbrushes sold are defective is 0.016.
Step-by-step explanation:
The probability of an event, say <em>E </em>occurring is:
Here,
n (E) = favorable outcomes
N = total number of outcomes
Let <em>X</em> = number of defective electric toothbrushes sold.
The number of electric toothbrushes that were delivered to a store is, <em>n</em> = 20.
Number of defective electric toothbrushes is, <em>x</em> = 3.
The number of ways to select two toothbrushes to sell from the 20 toothbrushes is:
The number of ways to select two defective toothbrushes to sell from the 3 defective toothbrushes is:
Compute the probability that the first two electric toothbrushes sold are defective as follows:
P (Selling 2 defective toothbrushes) = Favorable outcomes ÷ Total no. of outcomes
Thus, the probability that the first two electric toothbrushes sold are defective is 0.016.