What is 400 percent of 7.8 - step by step solution

To get the solution, we are looking for, we need to point out what we know.

1. We assume, that the number 7.8 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 7.8 is 100%, so we can write it down as 7.8=100%.
4. We know, that x is 400% of the output value, so we can write it down as x=400%.
5. Now we have two simple equations:
1) 7.8=100%
2) x=400%
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:
7.8/x=100%/400%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for what is 400% of 7.8

7.8/x=100/400
(7.8/x)*x=(100/400)*x       - we multiply both sides of the equation by x
7.8=0.25*x       - we divide both sides of the equation by (0.25) to get x
7.8/0.25=x
31.2=x
x=31.2

now we have:
400% of 7.8=31.2