Answer:
It is a combination answer
495 ways
Step-by-step explanation:
In this question, we are tasked with calculating the number of ways in which a manager can select 4 people out of 12 for the Sunday evening shift.
Firstly, the question talks about selecting a particular number from a mix, this is a combination question since the key word SELECT is mentioned.
Now, how do we go about it? To select a partial number from a mix , we use the combination formula as stated.
Mathematically, say we are selecting a number r from a total of numbers n, the number of ways we can do this is nCr = n!/(n-r)!r!
In this case however, we are simply selecting 4 out of 12
Our combinational equation thus becomes 12C4 = 12!/(12-4)!4! = 12!/8!4! = 495 ways
Answer:
12
Step-by-step explanation:
let the number be a
30-3a= -6
collect the like terms
30+6=3a
3a=36
a=12
The number is 12
The answer is B
Because if you use your calculation right you would end up with 16,463
Let length = l
width = w
length = 3 times width = 3w
Area of the land = 75 sq. m
Area = length × width = 3w×w = 75
3w²=75
w²=25
w=5 m
length = 3×15 = 15m
Now lets make the figure with the path of width x meters
(Refer the attached figure for easy understanding)
The inner length is the length of the rectangle reduced by x meters on either side due to the path
that is 15-x-x = 15-2x
the inner width is the width reduced by x meters in either side
= 5-x-x = 5-2x
Now lets calculate the inner area = inner length × inner width
(15-2x)×(5-2x)
=
= sq. m
Now the function to calculate the cost
f(x) is given by $3.00 × area of the inner land
f(x) = 3 × {75-40x+4x²)
= 225-120x+12x²
or
= 12x²-120x+225