To calculate 40 percent of the number 1380, we need to create a ratio from which we can easily determine the value we are looking for.
We first create two simple equations with data we know.
1380 equals 100%, so we can save it as 1380 = 100%
The value we are looking for can be called x
We now know that x is 40 of the output value, so we can write it as x = 40.
So we have two simple equations:
1) 1380=100%
2) x=40%
When we compare these two equations, we get:
1380/x=(100%)/(40%)
Now we just have to solve the simple equation.
We calculate 40 percent of 1380:
1380/x=100/40
(1380/x)*x=(100/40)*x
1380=2.5*x
1380/2.5=x
552=x
x=552
Solution:
40 percent o 1380=552