0.4 is what percent of 280 - 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 280 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 280, so we can write it down as 100%=280.
4. We know, that x% equals 0.4 of the output value, so we can write it down as x%=0.4.
5. Now we have two simple equations:
1) 100%=280
2) x%=0.4
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%=280/0.4
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 0.4 is what percent of 280

100%/x%=280/0.4
(100/x)*x=(280/0.4)*x       - we multiply both sides of the equation by x
100=700*x       - we divide both sides of the equation by (700) to get x
100/700=x
0.14285714285714=x
x=0.14285714285714

now we have:
0.4 is 0.14285714285714% of 280