An MBA math problem Thank you

When the water depth is h, the radius of the proportional top circle is 2h, then the volume of the cone is.

v=1 3sh=1 3* *4h 2*h=4 3*h 3 Differentiation of both sides with respect to t.

dv/dt=4πh^2*dh/dt

Because dh dt = m hour, h = 30 m.

So. dv dt=72 cubic meters hour.

When the water depth is 30 meters, all the water flowing out is: (50*.)

Duration: 20 hours.

So the flow rate is: 396960 1000 = cubic meter hour.

Thank you very much, very valuable advice. I have been on the job for many years and am now preparing for the full-time MBA in January '14. Wish to study full-time on a full-time basis.

Now I have bought the mechanical engineering mathematics book and the Beihang High Score Guide, and I am ready to start reviewing from the real questions. It took me a month to go through the past few years of logic questions, and I'm ready to start reviewing math now. I feel that there are many and flexible knowledge points and problem-solving methods for elementary numbers, and the amount of knowledge is much larger than logic.

However, because of work, I can't devote myself to studying around the clock, so I can only find time to do problems in my spare time, so I want to improve my efficiency and solve mathematics as soon as possible, especially to bring up mathematical thinking first. Thank you both for your kind help. In the past, I was very superstitious about the role of real questions, but to be on the safe side, it seems that I still have to thoroughly understand the knowledge points of the exam textbook.

MBA Mathematics is all multiple-choice questions, each question is worth 3 points, a total of 25 questions. No big deal.

However, although there is no big problem, it is not so easy to choose the right one.

There are 7 ways to get the MMA math multiple-choice questions easily:

1.Direct push method

The direct derivation method is the direct analysis and derivation method. The direct extrapolation method is based on the conditions, using relevant knowledge, directly analyzing, deriving or calculating the results, so as to make correct judgments and choices. This is the most basic, most commonly used, and most important method.

Applicable question types: This method is generally used for calculation multiple-choice questions, and this method is also commonly used for other questions.

2.Reverse extrapolation

The reverse deduction slag shed method is the reverse derivation or reverse substitution method. The inverse method is to reverse the conditions by the options (i.e., the options of the multiple-choice questions), and the options that contradict the conditions are excluded, and the ones that coincide are the correct options, or one or several options are substituted into the question conditions in turn for verification and analysis, and the ones that coincide with the question conditions are the correct options.

3.Counter-evidence

If a contradiction can be introduced if one of the four options in a multiple-choice question is incorrect (or correct), it means that the option is correct (or incorrect). Choosing which option to start with is a matter of analysis and judgment based on the conditions of the question, and may sometimes require some intuition.

4.Counter-examples

If an option is a proposition, sometimes a counterexample is all it takes to exclude the option or to state that the proposition is false. Counter-examples are usually given with some commonly used, relatively simple but illustrative examples. If you pay proper attention to accumulating different counterexamples related to each knowledge point when you are reviewing or doing questions, Sakura Naka may come in handy in the exam.

5.Special case method (special value method).

If the question is a proposition with a general character, you can try to take one or several special cases and special values to verify which options are true, which are false, or which are highly likely to be true or false, so as to make the right choice.

Applicable question types: (1) When the conditions and conclusions have a certain degree of universality, certain options can be determined or excluded by taking special cases; (2) When it is necessary to prove that a conclusion that is not established or is likely to be untenable is wrong by giving a counterexample; (3) For some questions that are difficult to make judgments, it is assumed that they are correct or not under special circumstances.

6.Number-form combination method

Draw the corresponding geometric figures according to the conditions, and analyze them in combination with mathematical expressions and figures, so as to make correct judgments and choices. This method is often used for multiple-choice questions related to geometric figures, such as: the geometric meaning of definite integrals, the calculation of double integrals, curves and surface integrals, etc.

7.Exclusion

If 3 of the 4 options can be excluded by one or more methods, the remaining one is of course the correct one, or 2 of the 4 options can be excluded first, and then the remaining 2 will be judged and selected.

The answer is a.

Let A complete x every day, B can complete y every day, C can complete z every day, set A's daily wage a, B every day B, and C every day C

A system of equations based on known information.

System of equations x+2y=1

4y+4z=1

2x+2z=5/6

Style. The addition of one and three brings Eq. 2 into the solution to obtain x=1 3, so A alone takes 3 days to complete the system of equations 2

2a+2b=2900

4b+4c=2600

2a+2c=2400

The solution is a=1000, so A alone takes 3 days to complete, and it takes 3000

Hello classmates. For engineering application problems, the examination is all elementary unary multiple function problems, which is not very difficult, mainly in the calculation to be more careful. This problem can first assume that A, B and C each need x, y, z days to complete the project, according to the corresponding number of days of cooperation, you can get a system of unary cubic equations, that is, x is 3 days, for the cost of the corresponding assumption that the daily cost is u, v, w, according to the meaning of the problem, you can also get the corresponding cost of the equation system to find that you can be 3000.

So the answer is a.

The area of the graph enclosed by the absolute value of the curve xy + 1 = x absolute + y absolute value is the solution, and gets:

Simplify both sides of the equation squared at the same time.

obtain [(xy) squared] + 1 = (x squared) + (y squared) shift terms, merge similar terms, obtain.

x squared) multiplied by (y squared - 1) = y squared - 1 categorical discussion.

When the square of y = 1, y = plus or minus 1

When the square of y is not equal to 1, x = plus or minus 1

Draw an image. The shape that is enclosed is a square with a side length of 2.

So the area is equal to 4

Note: (Absolute value of xy) = Absolute value of x multiplied by absolute value of y.

--When x and y are both greater than 0, the equation is xy+1=x+y, i.e., y(x-1)=x-1

So x=1 is constant, and when x is not equal to 1, the equation is y=1

So the image of the equation in the first quadrant is two straight lines x=1 and y=1, and the area enclosed by them is 1 (draw a plot yourself).

Because the positive and negative changes of x,y do not affect the form of the equation, the image is symmetrical with respect to the x,y axis, so the area of the whole graph is 1*4=4

Three o'clock in the afternoon.

Let the time taken from A to A be t. The velocity of A is x, and the velocity of B is y.

t=15/x，t=20/60+15/y+40/20+15/y,x=y+10。

From the above three equations, we can get x=5, y=15, and t=3. So, it was three o'clock in the afternoon.

This question is explained in detail in the Winning MBA, you can check it out.