N anonymous survey of college students was taken to determine behaviors regarding alcohol, cigarettes, and illegal drugs. The results were as follows: 865 drank alcohol regularly, 667 smoked cigarettes, 205 used illegal drugs, 420 drank alcohol regularly and smoked cigarettes, 113 drank alcohol regularly and used illegal drugs, 117 smoked cigarettes and used illegal drugs, 95 engaged in all three behaviors, and 318 engaged in none of these behaviors.

a) How many students were surveyed?

nothing

answer:   c ?

step-by-step explanation:

it is 10.6 according to my calculations

alright so i think for this one it would to draw it out. this may be hard for me to try and draw, but i will do my best on here:

        r

  /       |     \

notice how it forms 2 triangles inside one bigger triangle.

so if we know the angle spr is the same as psr that is saying the measure of angle p is the same as angle s. this means the big triangle psr is either isosceles or equilateral. in both cases, the triangle is perfectly symmetrical when split down the middle, which is in this case rq. because we know it is perfectly symmetrical on both sides, we know that the two triangles inside the bigger one are equal.