Let’s call the number of gallons of 30% solution “x”. If we mix together 40 gallons and x gallons of solution, we’re going to come out with a total of 40 + x gallons of that 20% solution. Mathematically, this is
40(12%) + x(30%) = (40 + x)(20%)
With the percents as decimals:
40(0.12) + x(0.3) = (40 + x)(0.2)
Simplifying, we have:
4.8 + 0.3x = 8 + 0.2x
Collecting the x terms on one side and the constants on the other:
0.1x = 3.2
And multiplying both sides by 10 to find x:
x = 32
So, you’ll need 32 gallons of 30% solution to yield 40 + 32 = 72 gallons of 20% solution.
        
             
        
        
        
Answer:
n = -4
Step-by-step explanation:
-32=8n
Divide each side by 8
-32/8 = 8n/8
-4 = n
 
        
                    
             
        
        
        
Answer: 500 votes
Step-by-step explanation:
This can be shown by this formula.
300 is 60% of x. So if u can find the 100% by taking 300 and multiplying it by 100 which would be the 100% and dividing it by 60 which would be the 60%. The number that you get is how many didn't vote for Denise. Now just add these which would be 300+200 which would give you the answer above.
 
        
             
        
        
        
Answer:
720
Step-by-step explanation:
Since we are choosing a subset of 3 people from a set of 10 people, and arranging the 3 people according to relative strength, the answer can be obtained by computing P(10,3).
  
  P(10,3)=10! / (10-3)!
= 10!/7!
Rewrite  10
!  as  
10 * 9  * 8  * 7
!  / 7!
Cancel the common factor of  7
!  and divide (
10  * 9 * 8
) by  1
10  * 9  * 8 = 720
 
        
             
        
        
        
Answer:
Step-by-step explanation:
While some might feel that online learning is the fun leisurely form of schooling that grants tons of free time, it honestly gets old quick. Being in quarantine makes it all the more worse because you do nothing all day. On the subject of math though, it is a disservice to have to learn math online. Personally, it is my experience that having a physical teacher and classroom to learn with is crucial to ones mathematical ability, but it's not the end of the world, it won't last long and it won't affect you that bad. Sure, the benefits include having more control over your day which is a good source of preparation for college life and responsibilities of being an adult, but you lose daily interpersonal interactions and typical casual daily exercise, since you no longer walk to class. Nevertheless, we will push on.