Answer:
4. x=10
5. x=15
6. x=20
7. x=4
Step-by-step explanation:
4. 50+4x=90
90-50=40
40/4=10
x=10
5. (2x+60)+6x=180
6x+2x=8x
8x+60=180
180-60=120
8x=120
120/8=15
x=15
6. 3x+30=90
90-30=60
60/3=20
x=20
7. (8x+120)+7x=180
8x+7x=15x
15x+120=180
180-120=60
15x=60
60/15=4
x=4
The expected value of the game is its average earnings
- The expected value of a round is $2.23
- The expected value when the game is played 755 times is $1683.65
<h3>How to determine the expected value of a round</h3>
There are 12 cards with a value of 4 or less.
So, the probability of selecting a card with a value of 4 or less is:

The probability of selecting a card with a value more than 4 is the complement of the above probability.
So, we have:


The expected value is then calculated as:

Evaluate


Simplify

Hence, the expected value of a round is $2.23
<h3>The expected value when the game is played 755 times</h3>
In (a), we have:

In probability, we have:

So, we have:


Hence, the expected value when the game is played 755 times is $1683.65
Read more about expected values at:
brainly.com/question/15858152
Answer:
B. 50
Step-by-step explanation:
Answer:
3x +12
Step-by-step explanation: