There are 20 AAA batteries in a box and 7 are defective. Two batteries are selected without replacement. What is the probability of selecting a defective battery followed by another defective battery?

Answer :

Answer: 0.11

Explanation:

There are 20 AAA batteries in a box and 7 are defective. If two batteries are selected without replacement, the probability of selecting a defective battery will be 7/20.

The probability of selecting another defective battery will be 6/19 as there will be 19 batteries left and 6 defective.

Then, the probability of selecting a defective battery followed by another defective battery will be:

= 7/20 × 6/19

= 42/380

= 0.11