Answer:
20 is 80% of 25
Step-by-step explanation:
We assume, that the number 25 is 100% - because it's the output value of the task.
2. We assume, that x is the value we are looking for.
3. If 100% equals 25, so we can write it down as 100%=25.
4. We know, that x% equals 20 of the output value, so we can write it down as x%=20.
5. Now we have two simple equations:
1) 100%=25
2) x%=20
where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:
100%/x%=25/20
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.
7. Solution for 20 is what percent of 25
100%/x%=25/20
(100/x)*x=(25/20)*x       - we multiply both sides of the equation by x
100=1.25*x       - we divide both sides of the equation by (1.25) to get x
100/1.25=x
80=x
x=80
 
        
                    
             
        
        
        
5% of 235 is: 235*(5/100)= 235/20 = 11,75 or 5% of 470 is: 470/20 = 23,5
Total cost = 2*(235 + 11,75) = 2*246,75 = 493,5 or Total cost = 470 + 23,5 = 493,5
 
        
                    
             
        
        
        
Answer:
After the reflection over the line  y = -x, the image of the point is: (-3,-2)
Step-by-step explanation:
When a given point is reflected over a line the point only changes place but the distance between the point and the line remains same.
Let (x,y) be a point on the plane
and
y = -x be a line on the plane
When a point is reflected over a line y = -x , the coordinates of the point are exchanged which means x becomes y and y becomes x and both are negated
So (x,y) will become (-y,-x)
Given point is:
(2,3) 
After the reflection over the line  y = -x, the image of the point is: (-3,-2)
 
        
             
        
        
        
Answer:
1.6x10^-18 gram
Step-by-step explanation:
(5.3 x 10⁻²³ gram/molecule) x (20,000 molecule)
= (5.3 x 10⁻²³ x 2 x 10⁴) gram
= (10.6 x 10⁻²³⁺⁴) gram
= (1.06 x 10⁻²³⁺⁵) gram
= 1.06 x 10⁻¹⁸ gram
We need to find the mass of 20,000 molecules of oxygen. It can be calculated using unitary method. Here, we can multiply 20,000 molecules  by the mass of one oxygen molecule.