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3 years ago

Joseph drove for 3 hours at the speed of 40 km/h (kilometers

Mathematics

1 answer:

bezimeni [28]3 years ago

7 0

Answer:

250 km.

Step-by-step explanation:

Alright, so for this problem we can split it into two parts. Since distance = speed*time, the first 3 hours give us 3*40 or 120 km, and the last 2 hours give us 2*65, or 130 km. Adding these together, we get a final distance of 250 km.

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A box has 1 red marble, 3 blue marbles, and 4 green marbles. Maya draws a blue marble randomly from the box, replaces it, and th

allochka39001 [22]

Answer:

$\dfrac{9}{64}$

Step-by-step explanation:

Sampling with replacement means that we choose a marble, note its colour, put it back and shake the box, then choose a marble again.

There are $1+3+4=8$ marbles in total. The probability that the first chosen marble is blue is $\dfrac{3}{8}.$ then Maya replaces this marble and the probability of choosing the second blue marble is the same. Using the product rule, the probability of drawing 2 blue marbles in a row is

$\dfrac{3}{8}\cdot \dfrac{3}{8}=\dfrac{9}{64}.$

6 0

3 years ago

What is the answer of this equation ? 10x-6(2x+5)=20

Rudiy27

Answer:

Simplifying

x = -25

Step-by-step explanation:

Reorder the terms:

10x + -6(5 + 2x) = 20

10x + (5 * -6 + 2x * -6) = 20

10x + (-30 + -12x) = 20

Reorder the terms:

-30 + 10x + -12x = 20

Combine like terms: 10x + -12x = -2x

-30 + -2x = 20

Solving

-30 + -2x = 20

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '30' to each side of the equation.

-30 + 30 + -2x = 20 + 30

Combine like terms: -30 + 30 = 0

0 + -2x = 20 + 30

-2x = 20 + 30

Combine like terms: 20 + 30 = 50

-2x = 50

Divide each side by '-2'.

x = -25

6 0

3 years ago

A University wanted to find out the percentage of students who felt comfortable reporting cheating by their fellow students. A s

Alla [95]

Answer:

The point estimate for this problem is 0.48.

Step-by-step explanation:

We are given that a University wanted to find out the percentage of students who felt comfortable reporting cheating by their fellow students.

A survey of 2,800 students was conducted and the students were asked if they felt comfortable reporting cheating by their fellow students. The results were 1,344 answered "Yes" and 1,456 answered "no".

Let $\hat p$ = proportion of students who felt comfortable reporting cheating by their fellow students

Now, point estimate ( $\hat p$ ) is calculated as;

$\hat p=\frac{X}{n}$

where, X = number of students who answered yes = 1,344

n = number of students surveyed = 2,800

So, Point estimate ( $\hat p$ ) = $\frac{1,344}{2,800}$

= 0.48 or 48%

5 0

3 years ago

Evaluate h(x) = 17+ x/6 H(-18)=

yan [13]

The answer is 14

-18/6 is -3. add that to 17 and you get 14.

7 0

2 years ago

Solve 2cos ²y -siny -1=0 for 0° ≤y≤360°

natima [27]

$\displaystyle\bf\\2cos^2y -sin\,y -1=0~~~for~~0^o\leq y \leq360^o\\\\cos^2y=1-sin^2y\\\\2(1-sin^2y) -sin\,y -1=0\\\\2-2sin^2y-sin\,y-1=0\\\\-2sin^2y-sin\,y+2-1=0\\\\-2sin^2y-sin\,y+1=0~~~\Big|\times(-1)\\\\2sin^2y+sin\,y-1=0$

$\displaystyle\bf\\\boxed{\bf sin\,y=x}\\\\2x^2+x-1=0\\\\x_{12}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}=\frac{-1\pm\sqrt{1-4\cdot2\cdot(-1)}}{2\cdot2}=\\\\=\frac{-1\pm\sqrt{1+8}}{4}=\frac{-1\pm\sqrt{9}}{4}=\frac{-1\pm3}{4}\\\\x_1=\frac{-1+3}{4}=\frac{2}{4}=\boxed{\bf\frac{1}{2}}\\\\x_2=\frac{-1-3}{4}=\frac{-4}{4}=\boxed{\bf-1}\\\\sin\,y=\frac{1}{2}\\\\\boxed{\bf y_1=\frac{\pi}{6}~~or~~(30^o)}\\\\\boxed{\bf y_2=\frac{5\pi}{6}~~or~~(150^o)}\\\\sin\,y=-1\\\\\boxed{\bf y_3=\frac{3\pi}{2}~~or~~(270^o)}$

5 0

3 years ago