a bag contains 15 new batteries and 10 use batteries if Heather randomly so what's two batteries from the bag without replacement what is the probability that she will select a used battery and then a new battery​

1/4

Step-by-step explanation:

Probability is the number of desirable outcomes divided by the number of total outcomes. We can tell these events depend on each other because the batteries are picked without replacement. To find the probability of two dependent events, event that depend on each other, we can find the probability of the first event and the probability of the second event happens if the first is given and multiply them. In this case, the first event is selecting a used battery and the second is picking a new battery.

The total number of outcomes the basically the total amount of batteries that can be chosen. This is 15 + 10 or 25 outcomes. 10 of these batteries are used, and that would correspond to the amount of desirable outcomes because we want to pick a used one. From this, we can say the probability of picking a used battery is 10/25 which simplifies to 2/5.

To find the probability of picking a new battery after picking a used one, we can start by stating the amounts of each battery before the second draw. Since we already picked a used battery, our new totals will be 24 batteries, which 9 are used and 15 are new. Now, we can do the same thing a before, the number of desirable outcomes over the total. We get 15/24 which simplifies to 5/8.

To find the total probability, we multiply the two getting: 2/5 * 5/8 = 1/4.