6 phone numbers are possible for one area code if the first four numbers are 202-1
<u>Solution:</u>
Given that, the first four numbers are 202-1, in that order, and the last three numbers are 1-7-8 in any order
We have to find how many phone numbers are possible for one area code.
The number of way “n” objects can be arranged is given as n!
Then, we have three places which changes, so we can change these 3 places in 3! ways

Hence 3! is found as follows:

So, we have 6 phone numbers possible for one area code.
Answer:
umm... there is no problem
Solving a system of equations we will see that we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
<h3>
How many liters of each solution do we need to use?</h3>
First, we need to define the variables:
- x = liters of the 35% acid used.
- y = liters of the 80% acid used.
We know that we want to produce 60 liters of 65% acid, then we have the system of equations:
x + y = 60
x*0.35 + y*0.80 = 60*0.65
(in the second equation we wrote the percentages in decimal form).
To solve this we need to isolate one of the variables in one equation and then replace it in other one, isolating x we get:
x = 60 - y
Replacing that in the other equation:
(60 - y)*0.35 + y*0.80 = 60*0.65
y*(0.80 - 0.35) = 60*(0.65 - 0.35)
y*0.45 = 60*0.30
y = 60*0.30/0.45 = 40
So we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
If you want to learn more about systems of equations:
brainly.com/question/13729904
#SPJ1
Answer:
The Commutative property states that order does not matter. Multiplication and addition are commutative.
Step-by-step explanation:
4 + 2 = 2 + 4
5 + 3 + 2 = 5 + 2 + 3
b + a = a + b
Answer:
C:
Step-by-step explanation:
Both angles add up to 180°
<BCG + <BFG = 180°
2x+146+4x+238=180
6x+384 = 180°
6x = 180-384
6x = -204
Dividing both sides by 6
x = -34