Ask question

Ask question

All categories

2 years ago

5

Shelley compared the number of oak trees to the number of maple trees as part of a study about hardwood trees in a woodlot. She

counted 9 maple trees to every 5 oak trees. Later in the year there was a bug problem, and many trees died. New trees were planted to make sure there were the same number of trees as before the bug problem. The new ratio of the number of maple trees to the number of oak trees is 3:11. After planting new trees, there were 132 oak trees. How many more maple trees were in the woodlot before the bug problem than after the bug problem?

2 answers:

Sedbober [7]2 years ago

7 0

Answer:

72

Step-by-step explanation:

<u>Initial ratio of maple trees to oak trees</u>

9:5

<u>New ratio of maple trees to oak trees</u>

3:11

Number of oak trees = 132

<u>Number of maple trees</u>

132*3/11 = 36

<u>Total number of trees</u>

132+36 = 168

<u>Initial number of maple trees </u>

168*9/14 = 108

<u>The difference in the number of maple trees:</u>

108 - 36 = 72

kogti [31]2 years ago

4 0

Answer:

72 more trees before the bug problem

Step-by-step explanation:

The ratio was 9:5 before the bug problem and 3:11 after.

After the bug problem there were 132 oak trees,

m : 132 = 3 : 11

Then we know

m/132 = 3/11

Multiplying both sides by 132 cancels on the left

132 × (m/132) = (3/11) × 132

m = (3/11) × 132

Then solving for m

m = 132 × (3/11)

m = 36 This gives us the number of trees after the bug problem.

This would give us 168 trees in total, 132 oak, and 36 maple.

Since there is the same number of trees as before we calculate the number of maple and oak previously.

If Shelley counted 9 maple for every 5 oak we know that 9 out of 14 trees are maple and 5 out of 14 trees are oak.

9/14 = .6428 which is the percentage of maple trees before the bug problem.

We multiply .6428 x 168 (the total number of trees) and we get 108.

if there are 108 maple trees then 168-108 = 60 oak trees.

Further proof:

9:5 or 9/5 = 1.8 108/60 = 1.8

108 maple trees and 60 oak before the bug problem.

So 108 (maple before bug problem) and 36 maple trees after:

108 - 36 = 72 more trees before the bug problem

You might be interested in

Let P2 be the vector space of all polynomials of degree 2 or less, and let H be the subspace spanned by 10x2+4xâ1, 3xâ4x2+3, and

lord [1]

I suppose

$H=\mathrm{span}\{10x^2+4x-1,3x-4x^2+3,5x^2+x-1\}$

The vectors that span $H$ form a basis for $P_2$ if they are (1) linearly independent and (2) any vector in $P_2$ can be expressed as a linear combination of those vectors (i.e. they span $P_2$ ).

Independence:

Compute the Wronskian determinant:

$\begin{vmatrix}10x^2+4x-1&3x-4x^2+3&5x^2+x-1\\20x+4&3-8x&10x+1\\20&-8&10\end{vmatrix}=-6\neq0$

The determinant is non-zero, so the vectors are linearly independent. For this reason, we also know the dimension of $H$ is 3.

Span:

Write an arbitrary vector in $P_2$ as $ax^2+bx+c$ . Then the given vectors span $P_2$ if there is always a choice of scalars $k_1,k_2,k_3$ such that

$k_1(10x^2+4x-1)+k_2(3x-4x^2+3)+k_3(5x^2+x-1)=ax^2+bx+c$

which is equivalent to the system

$\begin{bmatrix}10&-4&5\\4&3&1\\-1&3&-1\end{bmatrix}\begin{bmatrix}k_1\\k_2\\k_3\end{bmatrix}=\begin{bmatrix}a\\b\\c\end{bmatrix}$

The coefficient matrix is non-singular, so it has an inverse. Multiplying both sides by that inverse gives

$\begin{bmatrix}k_1\\k_2\\k_3\end{bmatrix}=\begin{bmatrix}-\dfrac{6a-11b+19c}3\\\dfrac{3a-5b+2c}3\\\dfrac{15a-26b+46c}3\end{bmatrix}$

so the vectors do span $P_2$ .

The vectors comprising $H$ form a basis for it because they are linearly independent.

4 0

2 years ago

A group pre-orders 9 tickets for a sightseeing tour, even though they don't have the money to pay for them yet. Each ticket cost

MissTica

9x$32 + 15 is the total debt.
which would be $303.

3 0

2 years ago

Read 2 more answers

Asap pls help and explain

eduard

Answer:

the answer would be 90

Step-by-step explanation:

100 giants fills 5/8 (100/160) of the theater leaving 3/8 of the theater for the elves.

3/8 times 240 elves is 90 elves.

If there were 150 elves that would also be 5/8 filled plus the original 5/8 filled with 100 giants! Some elves might suffer!!!

4 0

2 years ago

Evaluate e − 1 2 f e− 2 1 fe, minus, start fraction, 1, divided by, 2, end fraction, f when e = 15 e=15e, equals, 15 and f = 2

ivolga24 [154]

The answer 456 fe
Because it the benefit is doing today

7 1

2 years ago

Read 3 more answers

1. Write an exponential function to represent the spread of Ben's social media post. 2. Write an exponential function to represe

Alex777 [14]

Answer:

1. y = 2(3)ˣ; 2. y = 10(4)^x; 4. Amber = 192 and 3 145 728;

Ben has 54 and 11 098; Carter = 80 and 10 249 shares;

5. Shifted up 45 shares; 6. Amber's;

7. Fewer friends. more shares.

Step-by-step explanation:

The general equation for an exponential function is

y = a(b)ˣ

1. Ben's function

The initial value a = 2.

6 = 2(b)¹ = 2b

Ben's function is

y = 2(3)^x

2. Carter's function

Carter shared his post with 10 friends on Day 0, so a= 10.

Each friend shared with 2 people each day, so b = 2.

Therefore, Carter's function is

y=10(2)ˣ

3. Graphs

$\begin{array}{cccc}& \textbf{Amber} &\textbf{Ben} & \textbf{Carter}\\\mathbf{x} & \mathbf{3(4)^{x}} &\mathbf{2(3)^{x}} & \mathbf{10(2)^{x}}\\0 & 3 & 2 & 10\\1 & 12 & 6 & 20\\2 & 48 & 18 & 40\\3 & 192 & 54 & 80\\\end{array}$

The figure below shows the graphs for each function.

4. Predictions

(a) Amber

(i) Day 3

y = 3(4)³ = 3 × 64 = 192

(ii) Day 10

y = 3(4)¹⁰ = 3 × 1 048 576 = 3 145 728

(b) Ben

(i) Day 3

y = 2(3)³ = 2 × 27 = 54

(ii) Day 10

y = 2(3)¹⁰ = 2 × 29 049 = 118 098

(c) Carter

(i) Day 3

y = 10(2)³ = 10 × 8 = 80

(ii) Day 10

y =10(2)¹⁰ = 10 × 1024 = 10 240

5. Sharing with assisted living facility

y = 3(4)ˣ + 45

The new graph will be shifted up by 45 units.

6. Fastest post

Amber's post travels the fastest.

After only two days, she already has more posts than anyone else.

By Day 10, she has more than 25 times the shares of her closest competitor.

7. Preference

It's not the number of friends you have, but the number of shares they make, that is the important factor.

Carter started with 10 friends, but they made only two shares.

Amber started with only three friends, but they made four shares. By Day 3, she had 192 shares compared to 82 for Carter and only 54 for Ben

If I had to choose, I would prefer a post with fewer friends initially but more shares, like Amber.

5 0

2 years ago