Question

How can we use 40% to help calculate 4%? 400% 1%?

Answer 1

what they said.........

Answer 2

To help find a percent of a whole number

1. out output value is 400

2. we represent the unkown value with x

3. from step 1 above 400=100%

4. similarly, x=40%

5. This results in a pair of simple equations

400=100%(1)

x=40%(4)

6. By dividing equation 1 by equation 2 and noting that both the RHS (right hand side) of both equations have the same unit (%); we have

`(400)/(x) = (100)/(40)`

7. Again, the reciprocal of both sides gives

`(4)/(400) = (40)/(100)`

⇒ x=160

Therefore, 40% of 400 is 160