Answer:
The age of the person who entered the room is 15
Step-by-step explanation:
We are given:
Ages of 5 people in a room are:
17, 16, 15, 17, 22
A person enters room, and then the mean age of 6 people is 17.
We need to find the age of person who entered the room.
The formula to calculate mean is: 
Now, in question we are given mean of 6 people that is 17
The age of 5 people are given while age of one person who enters the room is unknown.
Let age of person whose age is unknown= x
Now finding x using mean formula

So, The value of x: x=15
Hence, the age of the person who entered the room is 15
Answer:
A. (1.55, 2)
Step-by-step explanation:
The formula to apply when finding the midpoint of a segment where the coordinates of the end points are given is;

where (x₁,y₁) and (x₂,y₂) are the coordinates of the end points
Given;
x₁= -0.4 ,y₁=2.5, x₂=3.5, y₂=1.5 then applying the formula for midpoint

The solution to the problem is as follows:
For 3 notebooks you pay $1.98 so the ratio is 1:0.66.
For 10 notebooks, then we could scale the ratio and it will become 10:6.60. So they will cost you $6.60.
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
1 is a factor of 24, but not a multiple of 4
2 is a factor of 24, but not a multiple of 4
3 is a factor of 24, but not a multiple of 4
6 is a factor of 24, but not a multiple of 4