Answer:
0.0158 = 1.58% probability that all of them are under 18.
Step-by-step explanation:
Probability of independent events:
If three events, A, B and C are independent, the probability of all happening is the multiplication of the probabilities of each happening, that is:

The percentage of people under the age of 18 was 23.5% in New York City, 25.8% in Chicago, and 26% in Los Angeles.
This means that 
If one person is selected from each city, what is the probability that all of them are under 18?
Since the three people are independent:

0.0158 = 1.58% probability that all of them are under 18.
Plug the x value which is 2 back to the x and solve.
I gave you two answers because I wasn’t sure if the question was (x^2) - 2 or x^2-2.
Those two functions look similar but is totally different so keep that in mind.
Hope you have a victorious day!
Answer: She had 200 cards to start with
Step-by-step explanation:
Let x = the amount of cards she had initially. This means she had x cards to start with.
She gave half of the cards she had to a friend. This means she gave her friend x/2 cards. She is left with with (x-x/2) = x/2 cards.
She also gave 1/4 of the remaining cards to her brother. This means that she gave (1/4 × x/2) = x/8 cards to her brother.
Remaining number of cards will be x/2 - x/8 = (4x-x)/8 = 3x/8
She still has 75 cards left. This means
3x/8 = 75
Cross multiplying with 8, it becomes
3x = 75×8 = 600
x = 600/3 = 200
She had 200 cards to start with.