Robert takes medicine for an ear infection. There are 250,000 bacteria present when he begins taking the medicine, and 35% of the bacteria are destroyed every hour. How many hours will it take for 70% of the original bacteria to be destroyed?
A. 4 hours
B. 3 hours
C. 2 hours
D. 1 hour

geometry: triangles

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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

table 3 represents a direct variation function. : )

1/3 + 1/3 ≠ 2/6 because 1/3 alone = 2/6  

step by step explanation:

1/3 + 1/3 = 2/3       2/3=4/6