Carla can type 265 characters a minute on her computer keyboard.
at that rate, how many characters can she type in 15 minutes?
a 2,975
b 3,875
d 3,905
0 3,975

The answer is 3975

Step-by-step explanation:

See the picture below

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