Question

A survey of 250 adults found that during the last year, 70 traveled by plane but not by train, 70 traveled by train but not by plane, 20 traveled by bus but not by plane or by train, 45 traveled by bus and plane, 20 traveled by all three, and 185 traveled by plane or train. How many did not travel by any of these modes of transportation? and plane, 20 traveled by all three, and 15 traveled by blanc eled by plane but not by train, 95

Answer 1

By analyzing the given data and using set theory, we determined that 90 adults did not travel by plane, train, or bus in the last year.

Step-by-step explanation:

To solve this question, we need to find out how many adults did not travel by plane, train, or bus. We are given several subsets of people who use various combinations of these modes of transportation, and we can use a principle in set theory to determine the answer.

We know that 185 adults traveled by plane or train. This number includes those who traveled by both modes. There is an overlap of people who used all three modes, which is 20. So, to find the sole plane and train travelers, we subtract the people who used all three modes from those who traveled by plane but not by train and vice versa.

We calculate the number of plane-only and train-only travelers: 70 (plane only) + 70 (train only) - 20 (all three) = 120.

Since 185 traveled by either plane or train, the number that traveled by either without the bus is 185 - 20 (all three) = 165. The number that traveled by plane or train only is 165 - 45 (bus and plane) = 120.

Adding those who traveled by bus but not by plane or train (20) to those who traveled by all three (20) gives us 40. Therefore, 120 (plane or train only) + 40 = 160. To find out the number of adults who did not travel by any of these three modes, we subtract 160 from the total number of surveyed adults (250).

Finally, the number of adults who did not travel by any mode is 250 - 160 = 90.

Therefore, 90 adults did not travel by plane, train, or bus.

Answer 2

People who didn't travel by any mode = 45

Step-by-step explanation:

In the question,

Total number of people included in survey = 250

People who traveled by plane but not by train = 70

i.e.

a + e = 70

People who traveled by train but not by plane = 70

i.e.

c + d = 70

People who traveled by Bus but not by Plane or Train = 20

i.e.

f = 20 ..........(1)

People who traveled by bus and plane both = 45

i.e.

e + g = 45

People who traveled by all three = 20

i.e.

g = 20

People who traveled by Plane or Train = 185

i.e.

a + b + c + d + e + g = 185 ........(2)

So,

e = 45 - g = 45 - 20 = 25

e = 25

Now, on putting in eqn. (2) we get,

a + b + c + d + 25 + 20 = 185

a + b + c + d = 140 .......(3)

Now,

We need to find out,

Number of people travelling with any of these three is,

a + b + c + d + e + f + g

So,

On putting from eqn. (3) and (1), we get,

a + b + c + d + e + f + g = 140 + 25 + 20 + 20 = 205

So,

Number of people who didn't travel by any mode =Total people - Number of people travelling by any three

People who didn't travel by any mode = 250 - 205 = 45