..................................
Answer:
She should be expected to have 2.11 aces.
Step-by-step explanation:
I suppose there was a small typing mistake. It should be: On average she gets an ace of 8.44% of her serves.
Then
For each serve, there are only two possible outcomes. Either there is an ace, or there is not. The probability of there being an ace in a serve is independent of other serves. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:

She gets an ace of 8.44% of her serves.
This means that 
She attemps 25 serves:
This means that 
How many aces would you expect her to have

She should be expected to have 2.11 aces.
Answer: $12.63
Step-by-step explanation:
$14.87 + $7.76 = $22.63
2pizzas x $5 = $10
$22.63 - $10 = $12.63
Your tip for a bill that costs $80.50 at a 15% tip rate will be $12.06
Answer:
6.4
Step-by-step explanation:
By the Pythagorean Theorem:

Hope this helps!