I'm guessing the 20 percent off is from the $36.81 so you take 36.81 times 0.80 making it $29.448. Take 90 dollars and minus that amount.
Answer: $60.552
Rounded Answer: $60.55 or $60.60 or $61
Not sure if this helped, but yeah.....
You could use a simple calculator it's only 10.
C.
She said that I don’t need her 54
Answer : 0.0129
Step-by-step explanation:
Given : Based on FAA estimates the average age of the fleets of the 10 largest U.S. commercial passenger carriers is
years and standard deviation is
years.
Sample size : 
Let X be the random variable that represents the age of fleets.
We assume that the ages of the fleets of the 10 largest U.S. commercial passenger carriers are normally distributed.
For z-score,

For x=14

By using the standard normal distribution table , the probability that the average age of these 40 airplanes is at least 14 years old will be :-

Hence, the required probability = 0.0129