This problem can be expressed through the equation:
x+3x+10= 90
To solve it we subtract 10 on both sides
→x+3x=80
Add x and 3x
→4x=80
And divide each side by 4
→x=80/4
→x=20
ANSWER:
20
Answer:
Is an estimate of the average grams of salt used in 2012
Step-by-step explanation:
Let
x ---> the number of years since 2012
f(x) ---> is the total amount of salt ingested in grams
we have

This is a linear equation in slope intercept form
where
The slope is equal to

The y-intercept or initial value is equal to

The y-intercept is the value of the function f(x) when the value of x is equal to zero
In this context, the y-intercept is the average amount of grams of salt ingested in the year 2012
The exact value of the average amount of grams of salt ingested in the year 2012 is 3,554 grams (see the data in the table)
Compare the exact value with the y-intercept

therefore
3,548 grams Is an estimate of the average grams of salt used in 2012
Answer:
23.1% probability of meeting at least one person with the flu
Step-by-step explanation:
For each encounter, there are only two possible outcomes. Either the person has the flu, or the person does not. The probability of a person having the flu is independent of any other person. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
Infection rate of 2%
This means that 
Thirteen random encounters
This means that 
Probability of meeting at least one person with the flu
Either you meet none, or you meet at least one. The sum of the probabilities of these outcomes is 1. So

We want
. Then

In which



23.1% probability of meeting at least one person with the flu
Answer:
The amount of change she received was
dollar.
Step-by-step explanation:
Price of each carton of milk is
cents and she bought 3 cartons of milk.
We know that, <u>1 dollar = 100 cents</u>
So, 1 cent =
dollar.
and
cents
dollar.
Thus, <u>the total price of 3 cartons of milk</u>
dollar.
She gave the cashier $10.
So, the amount of change she received
dollar.