Alice baked a certain number of pies. She gave 1/8 of the pies to her friends and 1/4 of the remainder to her neighbor She was left with 63 pies. How many pies did Alice bake at first?

1 Answer
Apr 17, 2018

Original count of pies is 96

Explanation:

Let the original count of pies be represented by xx

She gave 1/818 of the pies to her friend
Thus for the remainder 'remove' 1/818 of the count -> x-x/8 xx8

A quarter of this given to the neighbour

So the remainder after this is:

color(green)((x-x/8)-(x-x/8)/4)(xx8)xx84

We are told that this count is 63. So we have:

color(green)((x-x/8)-(x-x/8)/4 = 63)(xx8)xx84=63
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

color(green)((x-x/8)-(x-x/8)1/4 = 63)(xx8)(xx8)14=63

color(green)((8x-x)/8-((8x-x)/8)1/4=63)8xx8(8xx8)14=63

color(green)((7x)/8-(7x)/32=63)7x87x32=63

color(green)([(7x)/8color(red)(xx1)]-(7x)/32=63 color(white)("dddd") -> color(white)("dddd")[(7x)/8color(red)(xx4/4)]-(7x)/32=63)[7x8×1]7x32=63dddddddd[7x8×44]7x32=63

color(green)((28x)/32-(7x)/32=6328x327x32=63

color(green)((21x)/32=6321x32=63

Multiply both sides by 32/213221

color(green)(x=32/cancel(21)^1xxcancel(63)^3)

color(green)(x=96)