Answer:
We need to remember that we have independent events when a given event is not affected by previous events, and we can verify if two events are independnet with the following equation:

For this case we have that:

And we see that 
So then we can conclude that the two events given are not independent and have a relationship or dependence.
Step-by-step explanation:
For this case we can define the following events:
A= In a certain computer a memory failure
B= In a certain computer a hard disk failure
We have the probability for the two events given on this case:

We also know the probability that the memory and the hard drive fail simultaneously given by:

And we want to check if the two events are independent.
We need to remember that we have independent events when a given event is not affected by previous events, and we can verify if two events are independnet with the following equation:

For this case we have that:

And we see that 
So then we can conclude that the two events given are not independent and have a relationship or dependence.
Answer:
15 girls
Explanation:
We know that the ratio of boys to girls in the classroom is 2:3, meaning that for every 2 boys there are 3 girls.
Now, we can set up a proportion to solve this problem.
Please see the picture attached.
I hope this helps!
You can change 24.5% by moving the decimal point
24.5%=.245
70,000 x .245=$17,150