Ask question

Ask question

All categories

2 years ago

5

A recipe for chili uses 2 cups of beans. Keith is making 1, times the recipe. Which equation helps Keith find how many cups of b

eans he needs?

1 answer:

Nonamiya [84]2 years ago

6 0

Answer:

2x1=2

Step-by-step explanation:

If it asks for 2, but he is making that one time he still needs to use 2.

You might be interested in

2. AB and DE are parallel. Angle BAC = 30 , angle CDE = 50. What is the measure of angle ACD?

inysia [295]

The correct answer is C. 80

3 0

2 years ago

Read 2 more answers

20 POINTS!!! Mr. Moore is installing new work benches in the wood shop. He wants the height of the benches to be best for studen

liubo4ka [24]

A: Suppose Mr. Moore decides to use 20 seventh graders as the sample. Is this sample a random sample? Explain your reasoning.

Ans: No, because he only chose the seventh graders which is invalid since he wants to have to use the mean height which involves the 6th, 7th and 8th graders.

B: Mr. Moore decides to use a random number generator to select 20 students from the school. Suppose that when choosing 20 students using the random generator on the graphing calculator, Mr. Moore’s sample is all eighth graders. Does that mean the sample is not a random sample? Explain your reasoning.

Ans: No, it is still a random sample. Since he is using a random generator, there is a possibility that the random generator would pick all students from the 8th grade. Unlike the first one, the random generator is not biased towards any grade, it is just a coincidence.

6 0

3 years ago

Read 2 more answers

1.morgan is 15 years old younger than Mrs.santtos their combined age is 442. jenny won the ping-pong championship eight more tim

swat32

If Morgan is 15 years younger then Mrs.Santos and there combined age is 442 that means that Mrs.Santos is 221, and Morgan is 206.

8 0

2 years ago

What is the mean of these numbers ? <br> 2,8,4,6,5

MrRa [10]

Answer:

5 is the mean

Step-by-step explanation:

4 0

2 years ago

A 500-gallon tank initially contains 220 gallons of pure distilled water. Brine containing 5 pounds of salt per gallon flows int

Wittaler [7]

Answer: The amount of salt in the tank after 8 minutes is 36.52 pounds.

Step-by-step explanation:

Salt in the tank is modelled by the Principle of Mass Conservation, which states:

(Salt mass rate per unit time to the tank) - (Salt mass per unit time from the tank) = (Salt accumulation rate of the tank)

Flow is measured as the product of salt concentration and flow. A well stirred mixture means that salt concentrations within tank and in the output mass flow are the same. Inflow salt concentration remains constant. Hence:

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = \frac{d(V_{tank}(t) \cdot c(t))}{dt}$

By expanding the previous equation:

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = V_{tank}(t) \cdot \frac{dc(t)}{dt} + \frac{dV_{tank}(t)}{dt} \cdot c(t)$

The tank capacity and capacity rate of change given in gallons and gallons per minute are, respectivelly:

$V_{tank} = 220\\\frac{dV_{tank}(t)}{dt} = 0$

Since there is no accumulation within the tank, expression is simplified to this:

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = V_{tank}(t) \cdot \frac{dc(t)}{dt}$

By rearranging the expression, it is noticed the presence of a First-Order Non-Homogeneous Linear Ordinary Differential Equation:

$V_{tank} \cdot \frac{dc(t)}{dt} + f_{out} \cdot c(t) = c_0 \cdot f_{in}$ , where $c(0) = 0 \frac{pounds}{gallon}$ .

$\frac{dc(t)}{dt} + \frac{f_{out}}{V_{tank}} \cdot c(t) = \frac{c_0}{V_{tank}} \cdot f_{in}$

The solution of this equation is:

$c(t) = \frac{c_{0}}{f_{out}} \cdot ({1-e^{-\frac{f_{out}}{V_{tank}}\cdot t }})$

The salt concentration after 8 minutes is:

$c(8) = 0.166 \frac{pounds}{gallon}$

The instantaneous amount of salt in the tank is:

$m_{salt} = (0.166 \frac{pounds}{gallon}) \cdot (220 gallons)\\m_{salt} = 36.52 pounds$

3 0

2 years ago