30 is what percent of 3840 - 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 3840 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 3840, so we can write it down as 100%=3840.
4. We know, that x% equals 30 of the output value, so we can write it down as x%=30.
5. Now we have two simple equations:
1) 100%=3840
2) x%=30
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%=3840/30
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 30 is what percent of 3840

100%/x%=3840/30
(100/x)*x=(3840/30)*x       - we multiply both sides of the equation by x
100=128*x       - we divide both sides of the equation by (128) to get x
100/128=x
0.78125=x
x=0.78125

now we have:
30 is 0.78125% of 3840