when a number is decreased by 40% of itself the result is 12 what is the number

Question

Word pro blew

Answer 1

Let X = the unknown number

 

Now you need to translate the English question into math:

 

"a number is decreased by 40% of itself" --> X - 0.4X

 

40% is the same as 0.4 - you move the decimal to the left two places.

 

"The result is 12" --> X - 0.4X = 12

 

Subtract the "X' terms --> 0.6X = 12

 

Divide both sides by 0.6 --> X = 20

 

Now you should check this answer by subtract 40% of 20 from 20 and see if you get 12.