Ask question

Ask question

All categories

2 years ago

3

Together, Bob and Tom take 4 hours to get the yard work done. If Bob works alone, it takes him 6 hours. How long would it take T

om, working alone, to do all of the yard work?
10 hours
12 hours
8 hours
9 hours

1 answer:

777dan777 [17]2 years ago

3 0

The answer is 12 and let me tell you how can you get to that conclussion:
<span>Let X be the number of hrs Tom takes to do it
Add their rates of working
( 1 yard ) / ( 6 hrs ) + ( 1 yard ) / ( X hrs ) = ( 1 yard ) / (4 hrs ) and then what you do is
1/6 + 1/x = 1/4
Remember to multiply both sides by 12x
then = 2x + 12 = 3x</span>

You might be interested in

The smaller rectangle was scaled by a factor of 2 to produce the larger figure. use the drop-down menus to show the missing dime

inessss [21]

If the rectangle is scaled by a factor of 2, it means that all of the sides are multiplied by 2. This means the length is changed from 6 to 12, and the width is changed from 2 to 4. The area however, is not 24, but 48, because BOTH the sides doubled.

5 0

2 years ago

Read 2 more answers

The area of the rectangle is 64.8 square centimeters. What is the perimeter of the rectangle? One group of ten tenths and one gr

9966 [12]

Answer:

(a) $Perimeter = 32.2\ cm$

(b) 100

Step-by-step explanation:

Solving (a):

Given

Shape: Rectangle

$Area = 64.8$

Required

Calculate the perimeter.

Area is calculated as:

$Area = L * W$

Where

$L = Length$ and $W = Width$

Substitute 64.8 for Area

$64.8 = L * W$

Make L the subject:

$L = \frac{64.8}{W}$

Perimeter is calculated as:

$P = 2 * (L + W)$

Substitute 64.8/W for L

$P = 2 * (\frac{64.8}{W} + W)$

$P = \frac{129.6}{W} + 2W$

To solve further, we take the derivative of P and set it to 0, afterwards.

$dP = -\frac{129.6}{W^2} + 2$

Set to 0

$0 = -\frac{129.6}{W^2} + 2$

Collect Like Terms

$\frac{129.6}{W^2} = 2$

Cross Multiply:

$2W^2= 129.6$

Divide through by 2

$W^2 = 64.8$

Take square roots

$W = \sqrt{64.8$

$W = 8.05$

Recall that:

$L = \frac{64.8}{W}$

So:

$L= \frac{64.8}{8.05}\\$

$L= 8.05$

The perimeter is:

$Perimeter = 2 * (8.05 + 8.05)$

$Perimeter = 2 * (16.10)$

$Perimeter = 32.2\ cm$

Solving (b):

Given

((1 Group of 10 tenths) and (1 group of 8 tenths))/(6 groups of 3 tenths)

Required

Solve

$Tenths = \frac{1}{10}$

So, the expression becomes:

((1 Group of $10 * \frac{1}{10}$ ) and (1 group of $8 * \frac{1}{10}$ ))/(6 groups of $3 * \frac{1}{10}$ )

This gives:

((1 Group of $\frac{10}{10}$ ) and (1 group of $\frac{8}{10}$ ))/(6 groups of $\frac{3}{10}$ )

Group means product, so the expression becomes:

$\frac{(1 * \frac{10}{10} \ and\ 1 * \frac{8}{10})}{6 * \frac{3}{10}}$

And, as used here means addition

$\frac{(1 * \frac{10}{10} + 1 * \frac{8}{10})}{6 * \frac{3}{10}}$

Simplify:

$\frac{(1 * 1 + 1 * 0.80)}{6 *0.30}$

$\frac{(1 + 0.80)}{1.80}$

$\frac{1.80}{1.80}$

$= 1.00$

7 0

2 years ago

It takes 5 carpenters 5 hours to make 5 chairs. How long would it take 100 carpenters to make 100 chairs?

Elza [17]

I hour because, one of the 5 carpenters built one chair in one hour, so one of the 100 carpenters would build one chair in one hour, there are only 95 more carpenters, nothing else different.
Hope I helped!

7 0

2 years ago

Read 2 more answers

Compare A and B if 70% of A is equal to $0.7a and 35% of B is equal to $0.35a

MrRa [10]

Answer:

A=B

Step-by-step explanation:

Equation 1: 70% of A = 0.7a

Equation 2: 35% of B = 0.35a

Equation 3 = (Equation 2) • 2

Equation 3: 70% of B = 0.7a

Equation 3 = Equation 1

A = B

3 0

2 years ago

Read 2 more answers

the volume of solid A is 28m3 and the volume of solid B is 1,792m3. If the solids are similar, what is the ratio of the surface

Maslowich

If k is the scale factor between the dimensions of the similar solids, the areas are related by k² and the volumes are related by k³. That is
$\ \ \dfrac{V_{a}}{V_{b}}=k^{3}$
$\ \ k=(\dfrac{V_{a}}{V_{b}})^{\frac{1}{3}}$

The areas are related by k², so
$\ \ \dfrac{A_{a}}{A_{b}}=k^{2} = (\dfrac{V_{a}}{V_{b}})^{\frac{2}{3}}$
$\ \ \dfrac{A_{a}}{A_{b}} = (\dfrac{28\ m^{3}}{1792\ m^{3}})^{\frac{2}{3}}=(4^{-3})^{\frac{2}{3}}$
$\ \ =4^{-2}=\dfrac{1}{16}$

The ratio of the surface area of solid A to that of solid B is ...
1/16

6 0

2 years ago