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3 years ago

What is the best estimate for V18

Mathematics

1 answer:

Sladkaya [172]3 years ago

3 0

Answer:

34/8-16/3-14/9

Step-by-step explanation:

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If triangle ABC is similar to triangle PQR, find the value of x and y.

tester [92]

Answer:

x = 9

y = 6

Step-by-step explanation:

ΔABC ~ ΔPQR

Therefore, corresponding sides of these similar triangles will be in the proportional.

$\frac{AB}{PQ}=\frac{BC}{QR}= \frac{AC}{PR}$

$\frac{6}{x}= \frac{4}{y}= \frac{8}{12}$

$\frac{6}{x}= \frac{8}{12}$

x = $\frac{12\times 6}{8}$

x = 9

Similarly, $\frac{4}{y}= \frac{8}{12}$

y = $\frac{12\times 4}{8}$

y = 6

6 0

3 years ago

You are a lifeguard and spot a drowning child 60 meters along the shore and 40 meters from the shore to the child. You run along

sukhopar [10]

Answer:

The lifeguard should run across the shore a distance of 48.074 m before jumpng into the water in order to minimize the time to reach the child.

Step-by-step explanation:

This is a problem of optimization.

We have to minimize the time it takes for the lifeguard to reach the child.

The time can be calculated by dividing the distance by the speed for each section.

The distance in the shore and in the water depends on when the lifeguard gets in the water. We use the variable x to model this, as seen in the picture attached.

Then, the distance in the shore is d_b=x and the distance swimming can be calculated using the Pithagorean theorem:

$d_s^2=(60-x)^2+40^2=60^2-120x+x^2+40^2=x^2-120x+5200\\\\d_s=\sqrt{x^2-120x+5200}$

Then, the time (speed divided by distance) is:

$t=d_b/v_b+d_s/v_s\\\\t=x/4+\sqrt{x^2-120x+5200}/1.1$

To optimize this function we have to derive and equal to zero:

$\dfrac{dt}{dx}=\dfrac{1}{4}+\dfrac{1}{1.1}(\dfrac{1}{2})\dfrac{2x-120}{\sqrt{x^2-120x+5200}} \\\\\\\dfrac{dt}{dx}=\dfrac{1}{4} +\dfrac{1}{1.1} \dfrac{x-60}{\sqrt{x^2-120x+5200}} =0\\\\\\ \dfrac{x-60}{\sqrt{x^2-120x+5200}} =\dfrac{1.1}{4}=\dfrac{2}{7}\\\\\\ x-60=\dfrac{2}{7}\sqrt{x^2-120x+5200}\\\\\\(x-60)^2=\dfrac{2^2}{7^2}(x^2-120x+5200)\\\\\\(x-60)^2=\dfrac{4}{49}[(x-60)^2+40^2]\\\\\\(1-4/49)(x-60)^2=4*40^2/49=6400/49\\\\(45/49)(x-60)^2=6400/49\\\\45(x-60)^2=6400\\\\$

$x$

As $d_b=x$ , the lifeguard should run across the shore a distance of 48.074 m before jumpng into the water in order to minimize the time to reach the child.

7 0

3 years ago

For a binomial distribution with p = 0.20 and n = 100, what is the probability of obtaining a score less than or equal to x = 12

notsponge [240]

The binomial distribution is given by,
P(X=x) = $(^{n}C_{x})p^{x} q^{n-x}$
q = probability of failure = 1-0.2 = 0.8
n = 100
They have asked to find the probability <span>of obtaining a score less than or equal to 12.
</span>∴ P(X≤12) = $(^{100}C_{x})(0.2)^{x} (0.8)^{100-x}$
where, x = 0,1,2,3,4,5,6,7,8,9,10,11,12
∴ P(X≤12) = $(^{100}C_{0})(0.2)^{0} (0.8)^{100-0} + (^{100}C_{1})(0.2)^{1} (0.8)^{100-1}$ + $(^{100}C_{2})(0.2)^{2} (0.8)^{100-2} + (^{100}C_{3})(0.2)^{3} (0.8)^{100-3}$ + $(^{100}C_{4})(0.2)^{4} (0.8)^{100-4} + (^{100}C_{5})(0.2)^{5} (0.8)^{100-5}$ + $(^{100}C_{6})(0.2)^{6} (0.8)^{100-6} + (^{100}C_{7})(0.2)^{7} (0.8)^{100-7}$ + $(^{100}C_{8})(0.2)^{8} (0.8)^{100-8} + (^{100}C_{9})(0.2)^{9} (0.8)^{100-9}$ + $(^{100}C_{10})(0.2)^{10} (0.8)^{100-10} + (^{100}C_{11})(0.2)^{11} (0.8)^{100-11}$ + $(^{100}C_{12})(0.2)^{12} (0.8)^{100-12}$

Evaluating each term and adding them you will get,
P(X≤12) = 0.02532833572
This is the required probability.

7 0

3 years ago

How is 17 + 26 different from 36 + 53? Explain ( this is regrouping lesson)

xxMikexx [17]

17+26 is different from 36+53 by if you add 17+26 the sum would be 43. And if you add 36+53 the sum would also be 89. So that means the way how they are different is that the 17+26 and 36+53 has different kinds of sums. They have different kinds of sums because you are different numbers.
Hope this helped and if you need more help then just message me instead :)

6 0

3 years ago

Change the fraction to a decimal with division 1/10

Viktor [21]

Answer: 0.1

Step-by-step explanation: you only need to add zero to the first value,

for example if you have 1/10, you add zero, getting the next equation

10/10 if you add a zero to value you can add a zero to the result getting the following result

10/10=0. in this point both values are divisible

and 10 between 10 is equal to 1

as you finish add zeros you can add a point and after the 1 getting this result

1/10 = 0.1

7 0

3 years ago

Read 2 more answers