Recent questions and answers in Math

Give an example of relation which is reflexive but neither symmetric nor transitive.

answered Apr 11 by harishahmad6

1 answer

A square piece of tin of side 24 cm is to be made into a box without top by cutting a square from each corner and folding up the flaps to form a box. What should be the side of the square to be cut off so that volume of the box is maximum?

answered Apr 9 by rahulrkchauhan123456789

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A coin is based so that the head is 3 times as likely to occur as tail. If the coin is tossed three times, find the probabilty distribution of number of tails.

answered Mar 20 by akkhola2000

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A catering agency has two kitchens to prepare food at two places A and B. From these place " Mid-day meal' is to be supplied to three different schools situated at P, Q, R. The monthly requirements of the schools are respectively 40, 40 and 50 food packets. A packet contains lunch for 1000 students. Preparing capacity of kitchen A and B are 60 and 70 packets per month respectively. The transportation cost per packet for the kitchen to school is given below. How many packets from each kitchen should be transported to school so that the cost of transportation is minimum? Also find the minimum cost.

answered Mar 20 by prakashkumarsingh.ktr

1 answer

The function $ f(x)=2 log (x-2) - x^2+4x+1 $increases in the interval.\[(a)\;(1,2)\qquad(b)\;(2,3)\qquad(c)\;(5/2,3)\qquad(d)\;(2,4)\]

answered Mar 7 by ranjani.hogwarts

1 answer

The mean and variance of a binomial distribution are $ 4 \;and\;\frac{4}{3}.\;Find\;P(X\geq1).$

answered Feb 26 by Sumitchn007

1 answer

An open box is to be constructed by removing equal squares from each corner of a 3 metre by 8 metre rectangular sheet of aluminium and folding up the sides. Find the volume of the largest such box.

answered Feb 23 by pady_1

1 answer

The plane ax+by=0 is rotated about its line of intersection with the plane z=0 through an angle $\alpha$.Prove that the equation of the plane in its new position is $ax+by\pm \bigg(\sqrt {a^2+b^2}\tan \alpha\bigg)z=0$.

answered Feb 4 by sanjamdeep30

1 answer

A metal has a threshold wavelength of $6000 ^{\circ} A$. Calculate its 1) threshold frequency and 2) work function of the metal in eV.

answered Jan 31 by arunamansingh5

1 answer

In a game, a man wins a rupee for a six and loses a rupee for any other number when a fair die is thrown. The man decided to throw a die thrice but to quit as and when he gets a six. Find the expected value of the amount he wins / loses.

answered Jan 28 by sristijain30

2 answers

Solve the following differential equation : $ \cos^2\: x\large\frac{dy}{dx}$$+y=\tan x$

answered Jan 27 by chodadeepak14

1 answer

Prove that relation R defined on the set N of natural numbers by \[x\;R\;y \Leftrightarrow 2x^2-3xy+y^2=0\] is not symmetric but it is reflexive.

answered Jan 24 by nimmisivapuri.d5

1 answer

Let $f : A \rightarrow B$ be a given function. A relation R in the set A is given by $R = {(a,b) \varepsilon A \times A : f(a) = f(b)}.$ Check, if R is an equivalence relation.

answered Jan 24 by nimmisivapuri.d5

1 answer

Find the values of P so that the lines $ \Large\frac{1-x}{3}=\frac{7y-14}{2p}=\frac{z-3}{2}$ and $ \Large\frac{7-7x}{3p}=\frac{y-5}{1}=\frac{6-z}{5}$ are at right angles.

answered Jan 23 by adarsh06032000

1 answer

find the equation of the normal to the curve y=x^3+2x^2 at x=0 find the coo

asked Jan 18 by samwarke2000

0 answers

Two cards are drawn one by one without replacement from well shuffled pack of 52 cards. Find the probability distribution of the number of aces.

answered Jan 17 by mahawarravi036

2 answers

Probabilities of solving a specific problem independently by A and B are $ \frac{1}{2} \: and \frac{1}{3} $ respectively. If both try to solve the problem independently, find the probability that (i) the problem is solved (ii) exactly one of them solves the problem.

answered Jan 14 by next2unonu

1 answer

There are two bags I and II. Bag I contains 2 white and 3 red balls and Bag II contains 4 white and 5 red balls. One ball is drawn at random from one of the bags and is found to be red. Find the probability that it was drawn from bag II.

answered Jan 3 by zawude.tame

1 answer

True or False: If the determinant $\small\begin{vmatrix}x+a & p+u & l+ f\\y+b & q+v & m +g\\z+c & r+w & n + h\end{vmatrix}$ splits into exactly $k$ determinants of order $3$, each element of which contains online term,then the value of $k$ is $8$.

answered Dec 6, 2017 by priyanka.c

1 answer

Find the scalar components and magnitude of the vector joining the points $P (x_1, y_1, z_1)$ and $Q (x_2, y_2, z_2)$.

answered Dec 6, 2017 by priyanka.c

1 answer

Reshma wishes to mix two types of food P and Q in such a way that the vitamin contents of the mixture contains atleast 8 units of vitamin A and 11 units of vitamin B. Food P costs Rs. 60/kg and food Q costs Rs. 80/kg. Food P contains 3 units/kg of vitamin A and 5 units of vitamin B, while food Q contains 4 units/kg of vitamin A and 2 units/kg of vitamin B. Determine the minimum cost of the mixture.

answered Dec 2, 2017 by taha.ba16

1 answer

Evaluate : $ \begin{bmatrix} a+ib & c+id \\ -c+id & a-ib \end{bmatrix} $

answered Nov 22, 2017 by rabindrasinghrouth

1 answer

Find the differential equation of the family of ellipses having foci on y- axis and centre at the origin.

answered Nov 12, 2017 by sharmaeku25

1 answer

Find the equation of a curve passing through the origin given that the slope of the tangent to the curve at any point ( x, y ) is equal to the sum of the coordinates of the point

answered Nov 11, 2017 by debnathsunita69

1 answer

Four hydrogen nuclei combine to form a helium nucleus, what amount of energy in mev will a released in this process?

answered Oct 17, 2017 by balaramshil1

1 answer

Find the area of the smaller part of the circle $ x^2+y^2=a^2$ cut off by the line $ x=\large\frac{a}{\sqrt 2}$

answered Sep 15, 2017 by kushagrapatel1997

2 answers

Draw a plot showing the variation of photo electric current against the intensity of incident validation on a given photo sensitive surface.

answered Sep 4, 2017 by throttlespec

1 answer

A letter is known to have come either from TATA NAGAR or from CALCUTTA.On the envelope,just two consecutive letter TA are visible.What is the probability that the letter came from TATA NAGAR.

answered Jul 30, 2017 by Prathapchaithanya99

2 answers

A wire of length 36 cm is cut into two pieces. One of the pieces is turned in the form of a square and the other in the form of an equilateral triangle. Find the length of each piece so that the sum of the areas of the two be minimum.

answered Jul 28, 2017 by pady_1

1 answer

A retired person has 70000 to invest and two types of bonds are available in the market for investment. First type of bond yields an annual income of 8% on the amount invested and the second type of bond yields 10% per annum. As per norms, he has to invest minimum of 10000 in the first type and not more than 30000 in the second type. How should he plan his investment, so as to get maximum return after one year of investment. Make it an L.P.P. and solve the above problem.

answered Jul 28, 2017 by yashingrodiya1212

1 answer

Let N denote the set of all natural numbers and R be the relation on N x N defined by $ (a,b)R(c,d) \Leftrightarrow ad(b + c) = bc(a + d).$ Show that R is an equivalence relation on N x N.

answered Jul 20, 2017 by saurabh.kumarshukla1995

1 answer

Give an account of Hershey and Chase experiment. What did it conclusively prove? If both DNA and pro

answered Jul 5, 2017 by pady_1

1 answer

If the line ax+by+c = 0 is normal to the curve xy = 1 then \[(a)\;a>0,b>0 \qquad (b)\;a<0,b<0 \qquad(c)\;a<0,b>0\qquad(d)\;a<0,b<0.\]

answered Jul 5, 2017 by toshit.jain

1 answer

During reproduction, the chromosome number (2n) reduces to half (n) in the gametes and again the ori

answered Jun 14, 2017 by pady_1

1 answer

Form the differential equation of the family of circles having centre on $y$-axis and radius $3$ units.

answered Jun 5, 2017 by rslv8331

2 answers

The total revenue received from the sale of x units of a product is given by $ R(x) = 13x^2 + 26x + 15 $ Find the marginal revenue when x = 7.

answered Jun 3, 2017 by ranjani.hogwarts

1 answer

Find the area included between the parabolas $ y^2=4ax\;and\;x^2=4ay$

answered May 24, 2017 by sai.manohar044

1 answer

Find the equation of the plane passing through the point (1,6,3) and perpendicular to the plane 2x+3y-z = 7

answered May 22, 2017 by vikkyravi0106

1 answer

find intervals in which function given by f(x) = sin 3x where x belongs [0, pi/2] is 1 increasing 2 decreasing

answered May 13, 2017 by nikunjjain285

1 answer

The ground state energy of hydrogen atom is $-13.6\;eV$ 1.What are the potential and kinetic energy of an electron in the 3rd excited state? 2.If the electron jumps to the ground state from the third excited state, calculate the frequency of the photon emitted.

answered May 11, 2017 by balaramshil1

1 answer