Question

There are 12 students in a classroom, including the triplets Joey, Chloe, and Zoe. If 3 of the 12 are randomly selected to give speeches, what is the probability that Joey will be first, Chloe will be second, and Zoe will be third?

Answer 1

we know that

The probability of an event is the ratio of the size of the event space to the size of the sample space.

The size of the sample space is the total number of possible outcomes

The event space is the number of outcomes in the event you are interested in.

so

 P=size of the event space/size of the sample space

 

step 1

find the probability that Joey will be first

size of the sample size=12

size of the event space=1

P=1/12

step 2

find the probability that Chloe will be second

size of the sample size=12-1=11

size of the event space=1

P=1/11

step 3

find the probability that Zoe will be third

size of the sample size=11-1=10

size of the event space=1

P=1/10

step 4

Find the probability that Joey will be first, Chloe will be second, and Zoe will be third

P=(1/12)*(1/11)*(1/10)-----> P=1/1320-----> 0.00075------> 0.076%

the answer is

the probability that Joey will be first, Chloe will be second, and Zoe will be third is 0.00075 (0.076%)