The sum of the three numbers is 500. If the first number is 200, and the value of the second number is twice the value of the third number, find the value of the third number.
Define a variable ** Let's say the third number is x.
How much is the second and third number? ** The sum of the second and third number is 500-200 = <<500-200=300>>300
Write an equation ** Since the third number is x, the sum of the values of the second and third number is x+2x = 300
Combine like terms ** This is 3x=300
Divide by 3 ** The value of the third number is x=300/3
Divide by 3 ** x=<<100=100>>100
#### 100