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
I think the answer could possibly be a
Answer: Use the same recipe but just throw away 4 cupcakes
Answer:
306
Step-by-step explanation:
Word problem: Today the temperature dropped 13 °F. After this drop, the temperature was 74 °F. What was the original temperature outside before the drop?
Subtraction problem: x °F - 13 °F = 74 °F
Solve: x - 13 = 74
x - 13(+13) = 74 + 13
x = 87 °F