There are 135 people in a sport centre. 77 people use the gym. 62 people use the swimming pool. 65 people use the track. 27 people use the gym and the pool. 23 people use the pool and the track. 31 people use the gym and the track. 4 people use all three facilities. A person is selected at random. What is the probability that the person uses exactly one of the facilities?

The correct answer is .

Step-by-step explanation:

There are 135 people in a sport centre.

Let the experiment be to pick a person from the sport centre who only uses exactly one of the facilities.

Total number of possible outcomes = 135

For the gym:

77 people use the gym.

27 people use the gym and the pool.

31 people use the gym and the track.

4 people use all three facilities.

Total number of people using only the gym are 77 - ( 27 + 31 + 4) = 15

For the swimming pool:

62 people use the swimming pool.

27 people use the gym and the pool.

23 people use the pool and the track.

4 people use all three facilities.

Total number of people using only the swimming pool are 62 - ( 27 + 23 + 4) = 8

For the tracks:

65 people use the track.

23 people use the pool and the track.

31 people use the gym and the track.

4 people use all three facilities.

Total number of people using only the tracks are 65 - ( 23 + 31 + 4) = 7

A person is selected at random.

Favorable outcomes = 7 + 8 + 15 = 30

Probability that the person uses exactly one of the facilities = = .

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.

i think u have 12 apples sorry again i don't really know if it correct i'm just tryna hrlp people out.