A geologist has collected 10 specimens of basaltic rock and 10 specimens of granite. The geologist instructs a laboratory assistant to randomly select 15 of the specimens for analysis. What is the probability that all specimens of one of the two types of rock are selected for analysis?

The probability that all specimens of one of the two types of rock are selected for analysis is 0.0325

Step-by-step explanation:

Step 1

Given in the question that there are 10 specimens of basaltic rock and 10 specimens of granite.

The Total specimen sample collected =20

Step 2

The probability of selecting a basaltic rock is= 10 / 20 = 0.5

The probability of selecting a granite is= 10 / 20 = 0.5

So, the probability mass function of the number of basalt specimens selected for analysis is given by

Step 3

The probability that all specimens of one of the two types of rock are selected for analysis is given by the

sum of the probabilities that 10 basalt specimens and 5 igneous specimen is selected and the probabilities that 5 basalt specimens and 10 igneous specimen is selected.

The probability that 10 basalt specimens and 5 igneous specimen is selected is given by

The probability that 5 basalt specimens and 10 igneous specimen is selected is also given by

Therefore, the probability that all specimens of one of the two types of rock are selected for analysis is given by

Step 4

Multiplying 2 with the output

2(0.01625) = 0.0325

The probability that all specimens of one of the two types of rock are selected for analysis is 0.0325

answer: 75°

step-by-step explanation:

∠esk is the supplement of ∠edk, so is 100°. ∠esd = 1/2·arc ed, so is 25°.

since ∠esk = ∠esd + ∠dsk

you have 100° = 25° + ∠dsk . .

fill in known values 75° = ∠dsk . . . . .

subtract 25°

step-by-step explanation:

the answer is a and d