Each Saturday, a store reduces the price of any unsold item by
10%. If an item was priced at $80, on Saturday of the first week it
is marked down to $72. At the end of the second week, it drops
to $64.80, and at the end of the third week the price is decreased
to $58.32. If this continues for 10 weeks, what should be the
selling price for an item that was originally priced at $80?

a-$27.89
b-$30.99
c-$52.11
d-$8.00

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584

c) the median for town a 30" is greater than the median for town b 25"

step-by-step explanation:

town a, median = q2 = 30

town b, median - q2 = 25

so the median for town a 30" is greater than the median for town b 25"

ljn

step-by-step explanation: