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3 years ago

Why -4 x (-4) = 16 not -16? Simple...

1 answer:

4 0

The reason why it is a positive 16 and not a negative 16, is because when you multiply a negative number with another negative number you will always get a positive number. But, if you multiple a negative number with a positive number, you will get a negative. So, in order for you to get a -16, the equation would have to be -4*4=-16.

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Triangle A:B:C is 5:4:3

Nitella [24]

Answer: the angles are: 30, 45, 75

Step-by-step explanation:

the sum of the angles of a triangle is 180 degrees.

the angles are in a ratio of 3:4:5.

if you allow the number of degrees in the first angles to be 3x, this means that the number of degrees in the second angle is equal to 4x and the number of degrees in the third angle is equal to 4x.

since the sum of the angles in a triangle is equal to 180 degrees, this means that:

3x + 4x + 5x = 180 degrees which means that 12x = 180.

divide both sides of this equation by 12 and you get x = 180 / 12 = 15 degrees.

this means that the 3x angles is equal to 45 degrees and the 4x angle is equal to 60 degrees and the 5x angle is equal to 75 degrees.

45 + 60 + 75 = 180 degrees so we're good there.

45 / 60 is equal to 3/4

60 / 75 is equal to 4/5

the angles are in the ratio of 3 to 4 to 5 which is as originally assumed, so we're good all around and that's your answer.

the angles are:

30, 45, 75

the ratio of 3:4:5 means that:

the first angle is in a ratio of 3/4 with the second angle.

the second angle is in a ratio of 4/5 with the third angle.

the first angle is in a ratio of 3/5 with the third angle.

the ratio of the first angle with the third angle is equal to 45/75.

simplify that by dividing both numerator and denominator by 15 and you get 3/5.

7 0

3 years ago

Crawling Crayfish!

boyakko [2]

Answer: Crayfish, 25 s

Step-by-step explanation:

Given

The length of race is 60 cm

Flicker gets a 10 cm head-start

Cray fish covers 6 cm in 5 s i.e. its speed is

$\Rightarrow \dfrac{6}{5}=1.2\ cm/s$

Flicker covers 4 cm in 5 s, its speed is

$\Rightarrow \dfrac{4}{5}=0.8\ cm/s$

Time taken by Cray fish to cover the race is

$\Rightarrow t_1=\dfrac{60}{1.2}\\\\\Rightarrow t_1=50\ s$

Time taken by flicker to cover race with 10 cm head start

$\Rightarrow t_2=\dfrac{60-10}{0.8}\\\\\Rightarrow t_2=62.5\ s$

Time taken by crayfish is less. Hence, crayfish wins the race

When they both covers the same distance, they tied momentarily i.e.

$\Rightarrow 1.2t=10+0.8t\\\Rightarrow 0.4t=10\\\\\Rightarrow t=\dfrac{10}{0.4}\\\\\Rightarrow t=25\ s$

After 25 s, they tied the race.

5 0

2 years ago

Which ratios correctly compare bananas to apples, as<br> shown in the image? Check all that apply.

Oksana_A [137]

Answer:

where's the picture bro?

Step-by-step explanation:

7 0

2 years ago

If 30% of a number, n, is 120, what is 82% of n?

Naya [18.7K]

Answer:

1.28

Step-by-step explanation:

I did the math.

5 0

2 years ago

Read 2 more answers

The mean height of women in a country (ages 20-29) is 64 4 inches A random sample of 50 women in this age group is selected What

Simora [160]

Answer:

0.0721 = 7.21% probability that the mean height for the sample is greater than 65 inches.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .