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
The factorial ! just means we multiply by every natural number less that the value so
6! =6×5×4×3×2×1= 720
for permutations we use the formula n!/(n-r)!
so we have 8!/(8-5)!=8!/3!=8×7×6×5×4
for combinations s we have n!/(n-r)!r!
so we have 12!/(12-4)!4!=12!/8!4!=12×11×10×9/4×3×2=11×10×9/2=99×5
Answer:
113.04 cm³
Step-by-step explanation:
diameter = 6cm
so radius = 3cm
Volume of sphere = 

= 4 * 3.14 * 3 * 3 *3 / 3
= 4 * 28.26
= 113.04 cm³
5c plus 9c is 14c bc 5 plus 9 is 14 and the exponent is c so 14c
First notice that the triangle with sides

and the triangle with sides

are similar. This is true because the angle between sides

in the smaller triangle is clearly

, while the angle between sides

in the larger triangle is clearly

. So the triangles are similar with sides

corresponding to

, respectively.
Now both triangles are

, which means there's a convenient ratio between its sides. If the length of the shortest leg is

, then the length of the longer leg is

and the hypotenuse has length

.
Since

is the shortest leg in the larger triangle, it follows that

, so