Answer:
The cost of the diamond last year is x = $ 830
Step-by-step explanation:
Let the cost of diamond last year = x
the cost of diamond present year = y
Given that diamond today cost ten dollars more than twice what it cost last year.
⇒ y = 2 x + 10 ------ (1)
The sum of the cost (last year and this year) is = $ 2500
⇒ x + y = $ 2500 -------- (2)
Put the value of y in equation (2) from equation (1), we get
⇒ 2 x + 10 + x = $ 2500
⇒ 3 x = 2490
⇒ x = $ 830
& y = 2500 - 830
⇒ y = $ 1670
Therefore the cost of the diamond last year is x = $ 830
Using the binomial distribution, it is found that there is a 0.0328 = 3.28% probability that at least 2 of them choose the same quote.
<h3>What is the binomial distribution formula?</h3>
The formula is:


The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem, we have that:
- There are 6 students, hence n = 6.
- There are 20 quotes, hence the probability of each being chosen is p = 1/20 = 0.05.
The probability of one quote being chosen at least two times is given by:

In which:
P(X < 2) = P(X = 0) + P(X = 1).
Then:



Then:
P(X < 2) = P(X = 0) + P(X = 1) = 0.7351 + 0.2321 = 0.9672.

0.0328 = 3.28% probability that at least 2 of them choose the same quote.
More can be learned about the binomial distribution at brainly.com/question/24863377
4, -8
add the x's and add the y's
Answer:
y=5/2
Step-by-step explanation:
Answer:
210
Step-by-step explanation: so 5 times 12 120 plus 100 is 210