How many cookies had Kathy baked?

Question

Kathy bake cookies. Her brother took 1/2, her sister took 2/3 and mom took 1/2 leaving 5 cookies for kathy. 

Answer 1

This is not possible. 1/2 + 1/2 + 2/3 = 1 and 2/3  = 5/3 > 1

 

X = 1/2 X + 2/ 3 X + 1/2 X + 5

 

 

X = 5/3 X + 5

 

0 = 5/3 X + 5 - X

 

0 = 2/3X + 5

 

-5 = 2/3 X

 

X = -15/2

 

There are -15/2 cookies total.

 

Brother took (1/2) (-15/2) = -15/4

Sister took   (2/3)(-15/2) = -5

Mom took  -15/4

 

 Altogether -15/4 + -5 + -15/4 + 5 = -30/4 + -20/5 + 5 = -50/4 + 5 = -25/2 + 5 = -12.5 + 5 = -7.5 = -15/2

So the algebra checks out.

 

Check your numbers and repost