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3 years ago

Yesterday,there were 30 problems assigned for math homework

Mathematics

2 answers:

VashaNatasha [74]3 years ago

8 0

Answer:

Step-by-step explanation:

10 % = .1

30 x .1 = 30.0 -> 3.00

move decimal one place to the left!

Allushta [10]3 years ago

4 0

She got three questions wrong

You might be interested in

Find the surface area and round to the nearest hundredths place when necessary.

Step2247 [10]

Answer:

Let's find the area of 1 triangle (this may not be the formula but I'm doing it in a more easier way).

20(base) x 10.5(height) = 210

210 divided by 2 ( x 1/2) = 105

Since there are 4 sides we must multiply the area of 1 triangle four times! Since there are 4 sides of triangles.

105 x 4 = 420

Oh and I almost forgot! We need to find the area of the square below!

20 x 20 = 400!

Now we add both areas of all the triangles and the area of the bottom square:

420 + 400 = 820 in2 is your answer. (we use the unit 2 since we are finding areas and adding them up)

Formula of a triangle:

BH x 1/2

B(base) x H(height) x 1/2 (basically just dividing by 2)

7 0

3 years ago

There are 6 students. 2 of them are chosen for the position of president and Vice President. How many ways do we have to choose

Nutka1998 [239]

We have 15 ways to chose 2 students for the position of president and Vice President

Solution:

Given that,

There are 6 students. 2 of them are chosen for the position of president and Vice President.

To find: number of ways we have to choose the students from the 6 students

So now we have 6 students, out of which we have to choose 2 students

As we just have to select the students. We can use combinations here.

In combinations, to pick "r" items from "n" items, there will be $^{\mathrm{n}} \mathrm{C}_{\mathrm{r}}$ ways

$^{\mathrm{n}} \mathrm{C}_{\mathrm{r}}=\frac{n !}{(n-r) ! r !}$

Then, here we have to pick 2 out of 6:

Total students = n = 6

students to be selected = r = 2

$\begin{aligned} 6 C_{2} &=\frac{6 !}{(6-2) ! 2 !} \\\\ 6 C_{2} &=\frac{6 !}{4 ! 2 !} \\\\ 6 C_{2} &=\frac{6 \times 5 \times 4 \times 3 \times 2 \times 1}{4 \times 3 \times 2 \times 1 \times 2 \times 1} \\\\ 6 C_{2} &=15 \end{aligned}$

Thus we have 15 ways to chose 2 students for the position of president and Vice President

3 0

3 years ago

Cálculo da equação 5 (x+1)=3 (x-1)

Lana71 [14]

Answer:

x=−4

Step-by-step explanation:

5(x+1)=3(x−1)

5x+5=3(x−1)

3 0

3 years ago

The greatest common factor of 16 and the positive integer n is 4, and the greatest common factor of n and 45 is 3. Which of the

Digiron [165]

Answer:

6 if 7 doesnt divide n, 42 otherwise. The only possible options are those 2.

Step-by-step explanation:

I will find the possible answers, since no options were given

$16 = 2^4$ , thus, 16 only has 2 as a prime divisor. We conclude that n = 4*k, with k an odd number. On the other hand, $45 = 3^2 * 5$ , since the greatest factor between n and 45 is 3, then 5 is not a divisor of n, and n has the form 3*j, with j not a multiple of 3. Since 3 and 4 doesnt have common primes as factors, then j = 4*l, with l odd.

Thus n = 12 * j, with j a number that satisfies:

3 is not a divisor of j
2 is not a divisor of j
5 is not a divisor of j

Note that $210 = 2*3*5*7$ . 12 is not factor of 210, but 6 is. j doesnt have any prime divisor in common with 210, with the exception, maybe, of 7. So the greatest common factor of them is 1 or 7, depending on weather 7 divides j (or equivalently, n) or not. Therefore, the greatest common factor of n and 210 could be 6, if 7 does not divide n, or 6*7 = 42, if 7 divides n.