Find each missing measure.

One person can do a certain job in 15 minutes and another person can do the same job in 30 minutes. How many minutes will it tak

Flauer [41]

Hello! Your answer is B, 10 minutes.

Say the x = minutes taken to do the job. You can set up an equation like this to solve this.

$\frac{1}{15} x + \frac{1}{30} x = 1$

This is representative of the situation. The fractions each represent how much each person does in a minute, and when they're multiplied by x, that's how much of the project they get done based off of the minutes they work together on the job. Add the two together, and you get how much of the project is finished in x amount of time. Set it equal to 1, as you are looking for 100% completion.

Once you have this equation, find a common denominator, add, and solve.

$\frac{1}{15} x + \frac{1}{30} x = 1$

$\frac{2}{30} x + \frac{1}{30} x = 1$

$\frac{3}{30}x = 1$

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

$x = 10$

Therefore, it will take them 10 minutes to do the job together.

Hope this helps!

8 0

3 years ago

Three of these expressions are equal to the volume of the barn shown. Which expression is not?

timurjin [86]

The statement that does not match the others is the one at lower right.

_____

The barn's volume can be decomposed into a rectangular prism and a triangular one. Thus the upper right expression is a true represenation of the barn's volume:

... Volume of triangular prism + Volume of rectangular prism

The volume of a rectangular prism is the product of its dimensions. The dimensions of the rectangular prism portion of the barn's volume are a, b, c, so the volume of that portion is ...

... Volume of rectangular prism = a·b·c

The volume of a triangular prism is the area of the triangular base multiplied by the length of the prism. Here, the triangular base has base dimension b and height (d-c), so its area is ...

... Area of triangular barn end = (1/2)b(d-c)

Since the length of the barn is "a", the volume of the triangular prism is ...

... Volume of triangular prism = (1/2)b(d-c)a = (1/2)·a·b·(d-c)

The total volume is the sum of the volumes of the parts ...

... a·b·c + (1/2)·a·b·(d-c) . . . . . . matches the upper right selection

This can be factored by removing a·b to outside parentheses:

... a·b·((1/2)·(d-c) + c) . . . . . . . . . matches the lower left selection

___

Since the two left selections match the one at upper right, the odd one is the one at lower left.

7 0

3 years ago

Read 2 more answers

3 times a number is 54 less than the square of that number. Find the negative solution.

Pavel [41]

Answer:

x=-6

Step-by-step explanation:

Let x be the number

3x = x^2 -54

Subtract 3x

3x-3x = x^2 -3x-54

0 = x^2 -3x-54

Factor

What 2 numbers multiply to -54 and add to -3

-9*6 = -54

-9+6 = -3

0=(x-9) (x+6)

Using the zero product property

x-9=0 x+6=0

x=9 x=-6

The questions asks for the negative solution

x=-6

3 0

3 years ago

Could x = -5 be a solution to the inequality -6 < 3x + 9 < 21?

musickatia [10]

Answer:

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Population Growth The population of a town of 5000

Nesterboy [21]

Answer:

a) $A=5000{(1.03)}^{t}$

b) 5464 inhabitants.

Step-by-step explanation:

The formula used for compound interest becomes very helpful in this case.

$A=P{(1+r)}^{t}\\\\When:\\A = Final Value\\P = Initial Value\\r = Rate of Change (Decimal)\\t = Time (Years)$

Knowing this, we can easily calculate the value for any year, counting from the original 5000.

From this formula, we can derive a specific one that will serve for any value of t.

a)

$A=5000{(1+0.03)}^{t}\\A=5000{(1.03)}^{t}$

b) Apply the formula:

$A=5000{(1.03)}^{3}\\A=5000(1.092727)\\A=5463.635=5464$

The town will have 5464 inhabitants.

5 0

3 years ago