Question

Justin lives in Saint Paul and goes to school in Minneapolis. In the morning, he has 3 transportation options (bus, cab, or train) to school, and in the evening he has the same 3 choices for his trip home.If Justin randomly chooses his ride in the morning and in the evening, what is the probability that he'll use both the bus and the train?

Answer 1

Answer:

2/9

Step-by-step explanation:

Number of transportation options Justin has = 3(Bus, Cab, Train)

Justin needs to travel up and down to school. So, he needs to pick either of the 3 transportation twice a day.

While Going to school:

The number of ways he could pick a transportation = 3

The probability that he could a pick a bus

= Number of way he could pick a bus/ Total number of possible ways

=1/3

Similarly, the probability that he could pick a train = 1/3

While coming back from school:

The probability that he could a pick a bus = 1/3

The probability that he could pick a train = 1/3

Probability that he'll use both the bus and the train to go up and down the school:

[(Probability the he picks up a bus while going to school) * (Probability the he picks up a train while coming from school)]

                                          +

[(Probability the he picks up a train while going to school) * (Probability the he picks up a bus while coming from school)]

= [(1/3) * (1/3)] + [(1/3) * (1/3)]

= (1/9) + (1/9)

= 2/9

Answer 2

Answer:

2/9

Step-by-step explanation:

Here are the combination of transportation that can be used by Justin to make his travel

• Going by bus in morning and coming back by bus in evening.

• Going by bus in morning and coming back by car in evening.

• Going by bus in morning and coming back by train in evening.

• Going by car in morning and coming back by bus in evening.

• Going by car in morning and coming back by car in evening.

• Going by car in morning and coming back by train in evening.

• Going by train in morning and coming back by bus in evening.

• Going by train in morning and coming back by car in evening.

• Going by train in morning and coming back by train in evening.

we can see the total number of events possible are = 9

According to question, the total number of favourable outcomes ( which involves transportation by both bus and train ) = 2

Hence, required probability

= Number of favourable outcomes/ Total number of outcomes

 = 2/9