The answer is C. 23 is a term
Answer:
(a) The expected number of guests until the next one pays by American Express credit card is 4.
(b) The probability that the first guest to use an American Express is within the first 10 to checkout is 0.0215.
Step-by-step explanation:
The random variable <em>X</em> can be defined as the number of guests until the next one pays by American Express credit card
The probability that a guest paying by American Express credit card is, <em>p</em> = 0.20.
The random variable <em>X</em> follows a Geometric distribution since it is defined as the number of trials before the first success.
The probability mass function of <em>X</em> is:

(a)
The expected value of a Geometric distribution is:

Compute the expected number of guests until the next one pays by American Express credit card as follows:



Thus, the expected number of guests until the next one pays by American Express credit card is 4.
(b)
Compute the probability that the first guest to use an American Express is within the first 10 to checkout as follows:


Thus, the probability that the first guest to use an American Express is within the first 10 to checkout is 0.0215.
4 to 7
or
4+7= 12
4x+7x=33
x=3
so,
(4×3)+(7×3)=33
12+21=33
or
12 and 21.
hope it helped
Answer: Nicole has 88 erasers in all
Step-by-step explanation:
Number of erasers that Nicole has = 83
Number of erasers given to Nicole= 5
Total number of erasers Nicole has in all = 83+5= 88 erasers
Therefore Nicole has 88 erasers.
If the amount of time taken to go said distance is x and the amount of time taken to go back said distance is y, then the amount of miles total is 7x+3y due to that for every hour, she adds 7 miles when going there and 3 miles for walking back. In addition, since the total amount of time is 4 hours, x+y=4 as the total time spent as well as 7x=3y due to that they're the same distance.
x+y=4
7x=3y
Dividing the second equation by 7, we get x=3y/7. Plugging that into the first equation, we get 3y/7+y=4=10y/7 (since y=7y/7). Multiplying both sides by 7 and then dividing both by 10, we get 28/10=2.8=y in hours. Since 0.1 hours is 60/10=6 minutes, and 0.8/0.1=8, 6*8=48 minutes=0.8 hours, meaning that she should plan to spend 2 hours and 48 minutes walking back