There are 10 AAA batteries in a box and 3 are defective. Two batteries are selected without replacement. What is the probability of selecting a defective battery followed by another defective battery?
A) ½ or 0.50
B) ¼ or 0.25
C) 1/120 or about 0.0083
D) 1/15 or about 0.07

Question

Quizplus · Accepted Answer

The probability of selecting the first defective battery is 3/10. After removing one defective battery, there are 2 defective batteries left out of 9 total batteries. So, the probability of selecting a second defective battery is 2/9. Multiply these probabilities: (3/10) * (2/9) = 1/15.

There Are 10 AAA Batteries in a Box and 3