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3 years ago

Circumference of a circle working out and awnser

Mathematics

1 answer:

Romashka-Z-Leto [24]3 years ago

5 0

Answer: $d = 2.75 cm$

Step-by-step explanation:

The formula for calculating the circumference of a circle is given as :

$C = 2\pi r$ , where r is the radius

$C =\pi d$ , where d is the diameter

using the second formula , since we are finding the diameter.

$C=\pi d$

that is

$8.64 = d(\frac{22}{7})$

multiply through by $\frac{7}{22}$

we have :

$d = \frac{7}{22}(8.64)$ $= 2.749090909$

rounded to 2 d.p

$d = 2.75 cm$

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-1/2(-3y+10) i need help combining like terms to create a equivelent expression

Vaselesa [24]

Answer:

1.5y - 5

Step-by-step explanation:

I used the distributive approach and distributed -1/2 to the -3y and 10.

(If you try this and it's incorrect, you may just need to distribute -1/2 to the 10, creating -3y - 5.)

6 0

3 years ago

A student scored 66 points on his Psychology 101 midterm. If the average of his midterm and final must be between 78 and 90 incl

masha68 [24]

Answer:

range of scores on final exam student get B is 90 to 100

Step-by-step explanation:

given data

Psychology 101 score = 66

average of his midterm = between 78 and 90

maximum = 100 points

to find out

range of scores on final exam student get B

solution

we consider here lowest marks need in final = x

so average at two marks should be

equation is

average marks = 0.5 × ( mid term marks + final marks ) .................1

put here value

78 = 0.5 × ( 66 + x )

x = 90

and

90 = 0.5 × ( 66 + x )

x = 114

so range 90 to 114

but maximum marks is 100 so

range of scores on final exam student get B is 90 to 100

5 0

4 years ago

Sung is going to rent a truck for one day. There are two companies he can choose from, and they have the following prices.

Alexus [3.1K]

Answer:

Step-by-step explanation:

Use the equation

89 < 75 + 0.7*M Subtract 75 from both sides

89 - 75 < 0.7M Combine

14 < 0.7 M Divide both sides by 0.7

14/0.7 < M

20 < M

If M goes over 20 then the flat rate is cheaper.

8 0

2 years ago

An experiment consists of rolling two fair number cubes. What is the probability that the sum of the two numbers will be >3

liraira [26]

Answer: $\bold{\dfrac{5}{12}}$

Step-by-step explanation:

greater than 3 means the sum is either 4, 5, or 6.

There are 15 permutations that meet the criteria:

(1, 3), (1, 4), (1, 5), (1,6)

(2, 2), (2, 3), (2, 4), (2, 5), (2,6)

(3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3,6)

(4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4,6)

(5, 1), (5, 2), (5, 3), (5, 4), (5, 5), (5,6)

(6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6,6)

There are 6²= 36 total permutations for 2 dice.

$Probability=\dfrac{\#\ of\ permutations> 3}{total\ \#\ of\ permutations}\\\\.\qquad \qquad =\dfrac{15}{36}\\\\.\qquad \qquad =\dfrac{5}{12}\\\\$

3 0

3 years ago

{HIGH PAYOUT} Can someone help by showing work on how to get to answer?

Gala2k [10]

Let's assume each line is one toothpick.

In figure 1, there is a square made out of the 4 toothpicks.

In figure 2, there are four squares made. However, the 4 four toothpicks were already used, so we don't count them twice. That gives 4 (that were used) + 3 (the new ones on the left) + 3 (new ones on top) + 3 (new ones on right). We sum them up: 4 + 3 + 3 + 3 = 13.

In figure 3 there are nine squares made. We have the 13 squares made, plus 3 on the left column, 2 on the left center column, 3, on the center column, 2 on the right center, and 3 on the right. We total them up. 13 + 3 + 2 + 3 + 2+ 3 = 26.

Let's look at the pattern.

Figure # # Toothpicks

1 4

2 13

3 26

From figure 1 to 2, we added 9. From 2 to 3 we added 13. If we draw figure 4, we would add (from left to right) 3, 2, 2, 3, 2, 2, 3. That would be 17 toothpicks added, and 39 total. Let's go back to the table.

Figure # # Toothpick

1 4

2 13

3 26

4 39

Now let's look at the sequence happening. As we add more, we increase by 9, then 13, then 17. For each row, we add the same number as the previous row and then add 4. Drawing Figure 5 would be too much, but we can conclude based on the pattern that 21 squares would be added. We can take this sequence as far as we need to. We want the 10th figure or term, so we apply the pattern and keep going until we get there.

Figure # # Toothpick

1 4

2 13 <--- add 9

3 26 <--- add 13, the same 9 and 4 more

4 39 <--- add 17, the same 13 and 4 more

5 60 <--- add 21, the same 17 and 4 more

6 85 <-- add 25, the same 21 and 4 more

7 114 <-- add 29, the same 25 and 4 more

8 147 <-- add 33

9 184 <---- add 37

10 225 <-- add 41

Thus the 10th figure has 225 toothpicks.

5 0

3 years ago