Answer:
Step-by-step explanation:
Here, 3.2 centimeters on the map is equivalent to 4 kilometers. We can use unitary method to find, how many kilometer/kilometers each centimeter corresponds to. Using the unitary method: Therefore, the scale of map represents 1.25 kilometers for each centimeter.
Answer:
6
Step-by-step explanation:
Substitute n for 3
A(n) = 3/2(-2)^(n-1)
A(3) = 3/2(-2)^(3-1)
A(3) = 3/2(-2)²
A(3) = 3/2(4)
A(3) = 12/2
A(3) = 6
From the description, you can get two equation that looks like this:
L= 2*W+6.7cm
Perimeter= 57.2cm
Using perimeter formula, you can put the first and second equation like this:
perimeter= 2L + 2W
57.2cm= 2(2*W+ 6.7)+2W
57.2cm= 4W+ 13.4+ 2W
57.2- 13.4= 6W
W= 43.8/6= 7.3 cm
L= 2W+ 6.7
L= 2*7.3 + 6.7= 21.3
Answer: <span>A. Length=21.3 cm; width=7.3 cm</span>
Answer:
Percentage of balls which are red = 80%.
Step-by-step explanation:
Let the probability of drawing a red ball be x then the probability of drawing a white ball is 1-x.
There are 5C3 = 10 ways of getting 3 reds in 5 draws so the probability of this is 10* x^3 * (1 - x)^2.
The probability of getting 1 red in 5 draws = 5C1 * x (1-x)^4.
The first probability is 32 times the last.
So we have the equation:
10x^3(1 - x)^2 / 5x(1 - x)^4 = 32
2x^2 / (1 - x)^2 = 32
2x^2 = 32(1 -x)^2
2x^2 = 32( 1 - 2x + x^2)
2x^2 = 32 - 64x + 32x^2
30x^2 - 64x + 32 = 0
15x^2 - 32x + 16 = 0
(5x - 4)(3x - 4) = 0
x = 0.8, 1.333...
The probability must be < 1 so x = 0.8 = 80%.
