Answer:
- 12 ft parallel to the river
- 6 ft perpendicular to the river
Step-by-step explanation:
The least fence is used when half the total fence is parallel to the river. That is, the shape of the rectangle is twice as long as it is wide.
72 = W(2W)
36 = W²
6 = W . . . . . . the width perpendicular to the river
12 = 2W . . . . the length parallel to the river
_____
<em>Development of this relation</em>
Let T represent the total length of the fence for some area A. Then if x is the length along the river, the width is y=(T-x)/2, and the area is ...
A = xy = x(T -x)/2
Note that the equation for area is that of a parabola with zeros at x=0 and at x=T. That is, for some fence length T, the area will be a maximum at the vertex of this parabola. That vertex is located halfway between the zeros, at ...
x = (0 +T)/2 = T/2
The corresponding area width (y) is ...
y = (T -T/2)/2 = T/4
Equivalently, the fence length T will be a minimum for some area A when x=T/2 and y=T/4. This is the result we used above.
Answer: c)
Step-by-step explanation:
This can be done through trial-and-error. Use the pythagoreas' theorem
and if the left side of the equation is equal to the right, that is the answer.
(Do take note that c is the longest side.)
a)


Since
, a) is wrong.
b)

Since
, b) is wrong.
c) (answer)

Since
, c) is correct.
d)

Since
, d) is wrong.
Answer:
Probability = 2/7
Step-by-step explanation:
AS the Venn diagram is not given in the question, the question is incomplete. I've attached the Venn diagram of this question below for a better understanding of the question and its solution.
In the Venn diagram we can see that
Costumers who like Cake = 10
Costumers who like Pie = 8
Costumers who like both = 4
So it means that
Total costumers who like Cake = 10 + 4 = 14
Total costumers who like Pie = 8 + 4 = 12
We have to find probabilty that a costumer who likes cakes also likes pie
So
Total costumers who like cake = 14
Costumers out of 14 who also like pie = 4
Probability = (No. of costumers who also like pie) / (Total costumers who like cake)
Probability = 4/14 = 2/7