6th grade math
posted by joey on .
A chocolate bar is separated into several equal pieces. If one person eats 1/4 of the pieces, and a second person eats 1/2 of the remaining pieces, there are six pieces left over. Into how many pieces was the original bar divided?

1  3/4 = 1/4
1/4 = 6 pieces
4 * 6 = 24
Let's see if that works 
6 + 12 + 6 = 24
Yep, it works! 
let the number of pieces be x
(1/4)x + (1/2)(1  (1/4)x) + 6 = x
x/4 + 3x/8 + 6 = x
multiply by 8
2x + 3x + 48 = 8x
x = 16
check
they eat 1/4 of 16, leaving 12
then they eat 1/2 of that , leaving 6
Ms Sue had 24.
eating 1/4 of that leaves 18
eating 1/2 of that would leave 9, not 6 
Here is another way to do it.
Let x = number of pieces.
Then x(1/4)x (1/2)*(3/4)x = 6
x(1/4)x(3/8)x = 6
multiply through by 8 to clear the fractions.
8x2x3x=48
3x = 48
x = 16 pieces.
CHECK:
(1/4)*16 = 4 were eaten by person #1.
That leaves 164 = 12 pieces.
The second person ate 1/2 of that or (1/2)*12 = 6
So the first person ate 4, the second person ate 6 which makes a total of 10 and that leaves 6 pieces if there were 16 initially. 
Oops  thanks, Reiny.
I didn't read very carefully. I missed the part about eating 1/2 of the REMAINING pieces.