Math Kangaroo Brazil 2020 Grade 7-8 Question. Please Solve both question 25 and 26

Answer:

$287.82

Step-by-step explanation:

60 * 2.30 = 138

30 * 2.75 = 82.5

34 * 1.98 = 67.32

138 + 82.5 + 67.32 = 287.82

Answer:

.38 or 38%

Step-by-step explanation:

I divided 44 by 116 then rounded

Answer: 38% of boys play an instrument.

Step-by-step explanation:

They are asking for the percentage of boys that play an instrument.

44 ÷ 116 = 0.379310...

Round to the nearest hundredth

0.38

Find the percentage

0.38 × 100 = 38 or 38%

Answer:

x = 55

Step-by-step explanation:

Since the sides of the shape are parallel, AngleC and AngleD will add up to 180° (see "parallel lines cut by a transversal" or maybe you have learned a big pile of parallelogram theorems)

Use this relationship to set up an equation.

2x + 20 + 50 = 180

combine like terms

2x + 70 = 180

subtract 70

2x = 110

divide by 2

x = 110/2

x = 55

x is 55

Answer:

The value of x is 55°

Step-by-step explanation:

Since we know that opposite angles of a parallelogram are equal

The sum of any two adjacent angles is supplementary. This means, ∠A + ∠B = 180°, ∠B + ∠C = 180°, ∠C + ∠D = 180°, and ∠D + ∠A = 180.

So,

∠C + ∠D = 180°

(2x + 20)° + 50° = 180°

2x + 70° = 180°

2x + 70° - 70° = 180° - 70°

2x = 110°

2x/2 = 110°

x = 55°

Thus, The value of x is 55°

Answer:

254.47

Step-by-step explanation:

A= 3.14 x r²

A = 3.14 x 9

A = 254.47

Hope this helps

Answer

254.3—- rounded

A= Pi times r squared - this is formula for area of circle

area=  3.14 Times 9 squared

3.14 times 81

254.3

make sure to substitute values!

I hope this helps!

Answer:

140

Step-by-step explanation:

7/.05 -140

Answer:2024

Step-by-step explanation: 44x46

Answer: 102

Step-by-step explanation:

Let the numbers be a, a+2 and a+4. Since the sum of three consecutive even numbers is 312, this will be:

a + a+2 + a+4 = 312

3a + 6 = 312

3a = 312 - 6

3a = 306

a= 306/3

a = 102

Therefore, the smallest number is 102.

Other numbers are 104 and 106.

Here we need to find the domain of the given function.

We will see that the domain is the set of all real numbers.

For a given function f(x), we define the domain as the set of possible inputs that we can use on the function.

Usually, we start by defining the domain as the set of all real numbers and then remove from the domain the numbers that cause "a problem" with our function.

Where these "problems" are undefined operations, like the logarithm of a negative number or a zero in a denominator.

Particularly, in our function: f(x) = (1/2)^x

We do not have a denominator that can become zero nor a function that has problems with some given values of x (the exponent of a number can be any real number).

Concluding, because there is no problem with any real value,  we can see that the domain is the set of all real numbers

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Answer:

you'll know bc your fridge will be broken

Step-by-step explanation:

Answer:

When there is footprints in the butter.

Step-by-step explanation:

1/x^7

Step-by-step explanation:

To the 7th power is positive. It's the first one.

Hope this helps, have a good day!

it is A because X is unknown u can put 0 as a denominator so it 1 the X is still unknown and your exponents are 0

Answer:

------------------------------

Given equation:

Its solutions are:

The product of the solutions is -15:

Answer: hello the list related to your question is missing hence i will give you a general answer that will enable to pick the correct option from the list you have.

answer :

The correct number from the list that corresponds to the null hypothesis will be a number ≥ P - value / critical value

The correct number form the list that corresponds to the alternate hypothesis will be a number ≤ P - value / critical value

Step-by-step explanation:

Determine the null and alternative hypothesis

Mean difference = 0.914

standard deviation = 1.496

duration of test = 2 days

n ( sample size ) = 40

assuming  99% confidence interval

critical value = 2.708 ( using excel function : TINV (0.01, 40 - 1 ) )

Given that the aim of the experiment is to determine the effect of alcohol on driving ability

H0 : μ : Impairs driving

Ha : μ : does not impair driving

Note :

when the P-value is  ≤ significance level we reject the Null hypothesis

while when the P-value is ≥ significance level we reject the alternate hypothesis

The correct number from the list that corresponds to the null hypothesis will be a number ≥ P - value / critical value

The correct number form the list that corresponds to the alternate hypothesis will be a number ≤ P - value / critical value

Answer:

I usually turn the fractions into a decimal. So it would turn into

.666 < x< .777

When you turn your answers into fractions, the only one that fits is C which is 3/4 or .75

Step-by-step explanation:

Answer:

-729

Step-by-step explanation:

sequence is to multiply by -3 to get next term

Answer:

The 95% confidence interval for the true proportion of businesses owned by women is (0.2763, 0.4037).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

A survey of businesses in a particular state found that out of 150 surveyed, 51 were owned by women.

This means that [tex]n = 150, \pi = \frac{51}{150} = 0.34[/tex]

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

The lower limit of this interval is:

[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.34 - 1.96\sqrt{\frac{0.34*0.66}{150}} = 0.2763[/tex]

The upper limit of this interval is:

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.34 + 1.96\sqrt{\frac{0.34*0.66}{150}} = 0.4037[/tex]

The 95% confidence interval for the true proportion of businesses owned by women is (0.2763, 0.4037).

Answer:

9. m(YZ) = 102°

10. m(JKL) = 192°

11. m<GHF = 75°

Step-by-step explanation:

9. First, find the value of x

4x + 3 = 3x + 15 (inscribed angle that are subtended by the same arc are equal based on the inscribed angle theorem)

Collect like terms

4x - 3x = -3 + 15

x = 12

4x + 3 = ½(m(YZ)) (inscribed angle of a circle = ½ the measure of the intercepted arc)

Plug in the value of x

4(12) + 3 = ½(m(YZ))

48 + 3 = ½(m(YZ))

51 = ½(m(YZ))

Multiply both sides by 2

51*2 = m(YZ)

102 = m(YZ)

m(YZ) = 102°

10. First, find the value of x.

7x + 5 + 6x + 6 = 180° (opposite angles in an inscribed quadrilateral are supplementary)

Add like terms

13x + 11 = 180

13x = 180 - 11

13x = 169

x = 169/13

x = 13

7x + 5 = ½(m(JKL)) (inscribed angle of a circle = ½ the measure of the intercepted arc)

Plug in the value of x

7(13) + 5 = ½(m(JKL))

96 = ½(m(JKL))

Multiply both sides by 2

2*96 = m(JKL)

m(JKL) = 192°

11. First, find x.

5x + 15 = ½(11x + 18) (inscribed angle of a circle = ½ the measure of the intercepted arc)

Multiply both sides by 2

2(5x + 15) = 11x + 18

10x + 30 = 11x + 18

Collect like terms

10x - 11x = -30 + 18

-x = -12

Divide both sides by -1

x = 12

m<GHF = 5x + 15

Plug in the value of x

m<GHF = 5(12) + 15

m<GHF = 60 + 15

m<GHF = 75°

Answer:

11.2

Step-by-step explanation:

We can use the pythagorean theorem to find b.

the formula is as follows:

a^2 + b^2 = c^2

We are given a is 10 and c is 15, so we can plug those two numbers in:

10^2 + b^2 = 15^2

Now, we can simplify and solve:

100 + b^2 = 225

b^2 = 125

b = √125

√125 is about 11.1803398875, and to the nearest tenth, this rounds to:

11.2

Answer: 1040

Step-by-step explanation:

just took 65 and mutiply 65$

Answer:

30.6km/h

Step-by-step explanation:

To change from m/s to km/h needs to multiple by 36/10

36/10 × 8.5

=30.6km/h

Using division operation, since Benjamin jogs at a pace of 16 minutes per mile, in 45 minutes he will jog 2.8 miles.

The division operation is one of the basic mathematical operations, including addition, subtraction, and multiplication.

The division operation involves dividing the dividend (the numerator) by the divisor (the denominator) to obtain the quotient (the result).

The distance between Benjamin and Felix = 35 miles

Benjamin's jogging pace or speed = 16 minutes per mile

Felix's jogging pace or speed = 10 minutes per mile

The number of miles that Benjamin can jog in 45 minutes = Time/Speed

= 2.8125 miles (45/16)

Thus, Benjamin will jog 2.8 miles in 45 minutes.

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Answer:

answer in link

Step-by-step explanation

alekscgi/x/Isl.exe

Answer:

6x + y = -8

Step-by-step explanation:

Equation of a line:

The equation of a line has the following format:

[tex]y = mx + b[/tex]

In which m is the slope and b is the y-intercept.

m = -6

So

[tex]y = -6x + b[/tex]

(-2, 4)

This means that when [tex]x = -2, y = 4[/tex]. We use this to find b.

[tex]y = -6x + b[/tex]

[tex]4 = -6(-2) + b[/tex]

[tex]b = 4 - 12 = -8[/tex]

So

[tex]y = -6x + -8[/tex]

[tex]6x + y = -8[/tex]

Answer:

1. a quantity that stands alone and is not changed by other quantities. most often x variable.

2. a quantity that changes depending on another quantity, as a result of the rule. most often the y variable

Step-by-step explanation:

Answer: A quantity that stands alone and is not changed by other quantities most often X variable.

A quantity that changes depending on another quantity, as a result of the rule most often Y variable.

Answer:

16/81

Step-by-step explanation:

Same as (2/3)^4

Answer:

-1/3

Step-by-step explanation:

Answer:

b = -8

Step-by-step explanation:

To determine the value of b, we can use the factoring method. We can factor the expression

(5b + 16)(b + 32) as (b + 8)(5b + 16).

Setting each factor to 0, we get b + 8 = 0 and 5b + 16 = 0.

Solving for b in the first equation, we get b = -8.

Substituting this value into the second equation, we get 5(-8) + 16 = 0, which simplifies to -40 + 16 = 0.

This equation is true only when the value of b is -8. Therefore, the value of b is -8.

Answer:

151

Step-by-step explanation:

Answer:

152 miles

Step-by-step explanation:

There are 2 Xs above 20 1/2, so she rode that distance twice. There are 3 Xs above 22 1/2, so she rode that distance three times. The other distances with Xs she only did once. We add up the distances for each X to get the total:

20.5 + 20.5 + 21.5 + 22 + 22.5 + 22.5 + 22.5 = 152 miles