All categories

3 years ago

If it takes eight men ten hours to build a wall, how long would it take four men?

Mathematics

2 answers:

zmey [24]3 years ago

8 0

Answer:

ha ha is it math question seriously or riddle if riddle the wall is already built by men they non time is taken by men.

Darya [45]3 years ago

4 0

Answer:

20 bc if 8 men took 10 hours then 4 men would take double the time

You might be interested in

Mario’s company makes unusually shaped imitation gemstones. One gemstone had 10 faces and 12 vertices. How many edges did the ge

Evgen [1.6K]

20 edges
F=12, V=10
V -E+F=2
10-E+12=2
-E+22=2
-E=-20
E=20

8 0

4 years ago

Read 2 more answers

I NEED HELP PLEASE! :)

Andrej [43]

Answer:

Perpendicular

Step-by-step explanation:

To tell if the lines are perpendicular/parallel, you must look at the slope, but in this case, you must first get y by itself, like so:

3x + 7y = 15

-3x - 3x

___________

7y = -3x + 15

Divide both sides by 7:

y = $\frac{-3}{7}x + \frac{15}{7}$

Now the other equation:

7x - 3y = 6

-7x -7x

_________

-3y = -7x + 6

Divide both sides by -3:

y = $\frac{7}{3} x - 2$

You can see that the lines are perpendicular because the slopes ( $\frac{-3}{7} x$ and $\frac{7}{3}$ ) are opposite reciprocals.

5 0

4 years ago

What are the factors of x^2-8x-20

kipiarov [429]

Answer:

(x+2)(x−10)

Step-by-step explanation:

x^2-8x-20

Factoring means something like this:

(x+_)(x+_)

Add together to get -8

Multiply together to get -20

think of the two numbers

Try 2 and -10:

2+-10 = -8

2*-10 = -20

Fill in the blanks of with 2 and -10 to get

(x+_)(x+_) = (x+2)(x−10)

I hope it's right!

6 0

3 years ago

F(x) =

sertanlavr [38]

To make things easier, first rewrite

f(x) = x / (x + 7/x) = x ² / (x ² + 7)

i.e. multiply f by x/x, which is valid because x can't be 0 anyway as it's outside the domain of f.

Now, by the quotient and chain rules, we get

f '(x) = ((x ² + 7) (x ²)' - x ² (x ² + 7)') / (x ² + 7)²

… = (2x (x ² + 7) - x ² (2x)) / (x ² + 7)²

… = (2x ³ + 14x - 2x ³) / (x ² + 7)²

… = 14x / (x ² + 7)²

f ''(x) = ((x ² + 7)² (14x)' - (14x) ((x ² + 7)²)') / ((x ² + 7)²)²

… = (14 (x ² + 7)² - (14x) (2 (x ² + 7)² (x ² + 7)')) / (x ² + 7)⁴

… = (14 (x ² + 7)² - (14x) (2 (2x) (x ² + 7)²)) / (x ² + 7)⁴

… = (14 (x ² + 7)² - 4x (14x) (x ² + 7)²) / (x ² + 7)⁴

… = 14 (x ² + 7)² (1 - 4x) / (x ² + 7)⁴

… = 14 (1 - 4x) / (x ² + 7)²

… = (14 - 56x) / (x ² + 7)²

6 0

3 years ago

Mallory is on a budget and wants to determine which cereal is a better buy. A 10-ounce box of Cereal A costs $2.70 and a 13-ounc

Scorpion4ik [409]

Answer:

Cereal A is cheaper by $0.15

Step-by-step explanation:

Cost of a 10-ounce box of Cereal A = $2.70

So,

Cost of a 1-ounce box of Cereal A = $\frac{2.70}{10}=\$0.27$

Cost of a 15-ounce box of Cereal A = $0.27(15)=\$4.05$

Also,

Cost of a 13-ounce box of Cereal B = $3.64

So,

Cost of a 1-ounce box of Cereal B = $\frac{3.64}{13}=\$0.28$

Cost of a 15-ounce box of Cereal B = $=0.28(15)=\$4.2$

Here,

Cost of a 15-ounce box of Cereal B - Cost of a 15-ounce box of Cereal A = $4.2-4.05=\$0.15$

Therefore,

Cereal A is cheaper by $0.15

8 0

3 years ago