Question

Ms Cohen gave a riddle: A string is 2 meters longer than a rod. Half of the rod is 1 meter shorter than half of the string. Is this true or false?

Answer 1

We are going to define the following variables.
 y: length of the string.
 x: length of the rod.
 We have the following equation:
 y = x + 2
 Half of the rod is 1 meter shorter than half of the string
 x/2 = y/2-1
 Let's rewrite equation 1 to see if it's true:
 y = x + 2
 (1/2) * y = (1/2) * (x + 2)
 (1/2) * y = (1/2) * x + 1
 (1/2) * x = (1/2) * y-1
 Answer
 this is true
 (1/2) * x = (1/2) * y-1