A geologist takes samples of two rocks from a mountainside. The gray rock has a volume 25% higher than that of the brown rock. However, the brown rock’s density is 80% greater than the gray rock’s density. If the gray rock has a mass of 5 grams, what is the mass of the brown rock, in grams? (Density is defined as mass divided by volume.)

i would say c is the best answer, hope it's right!

good luck! =)

cutie~

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560