The foci of the ellipse \frac{x^{2}}{16}+\frac{y^{2}}{b^{2}}=1 and the hyperbola \frac{x^{2}}{144}-\frac{y^{2}}{{81}}=\frac{1}{25} coincide, then the value of b^{2} is
The value of the sum \frac{1}{2\sqrt{1}+1\sqrt{2}}+\frac{1}{3\sqrt{2}+2\sqrt{3}}+\frac{1}{4\sqrt{3}+3\sqrt{4}}+...+\frac{1}{25\sqrt{24}+24\sqrt{25}} is
If \vec{a}=\hat{i}-\hat{k},\, \vec{b}=x\hat{i}+\hat{j}+(1-x)\hat{k} and \vec{c}=y\hat{i}+x\hat{j}+(1+x-y)\hat{k} , then [\vec{a} , \vec{b}, \vec{c}] depends on
Let \vec{a}=\hat{i}+\hat{j}+\hat{k}, \vec{b}=\hat{i}-\hat{j}+\hat{k} and \vec{c}=\hat{i}-\hat{j}-\hat{k} be three vectors. A vector \vec{v} in the plane of \vec{a} and \vec{b} whose projection on \frac{\vec{c}}{|\vec{c}|} is \frac{1}{\sqrt{3}}, is
Out of 2n + 1 tickets, which are consecutively numbered, three are drawn at random. Then the
probability that the numbers on them are in arithmetic progression is
The value of sin^{-1}\frac{1}{\sqrt{2}}+sin^{-1}\frac{\sqrt{2}-\sqrt{1}}{\sqrt{6}}+sin^{-1}\frac{\sqrt{3}-\sqrt{2}}{\sqrt{12}}+... to infinity , is equal to
In a right angled triangle, the hypotenuse is four times the perpendicular drawn to it from the opposite vertex. The value of one of the acute angles is
A is targeting B, B and C are targeting A. Probability of hitting the target by A, B and C are \frac{2}{3}, \frac{1}{2} and \frac{1}{3} respectively. If A is hit then the probability that B hits the target and C does not, is
A harbour lies in a direction 60° South of West from a fort and at a distance 30 km from it, a ship sets out from the harbour at noon and sails due East at 10 km an hour. The time at which the ship will be 70 km from the fort is
A professor has 24 text books on computer science and is concerned about their coverage of the topics (P) compilers, (Q) data structures and (R) Operating systems. The following data gives the number of books that contain material on these topics: n(P) = 8, n(Q) = 13, n(R) = 13,
n(P \cap R) = 3, n(P \cap R) = 3, n(Q \cap R) = 3, n(Q \cap R) = 6, n(P \cap Q \cap R) = 2 where n(x) is the cardinality of the set x. Then the number of text books that have no material on compilers is
Two towers face each other separated by a distance of 25 meters. As seen from the top of the first tower, the angle of depression of the second tower’s base is 60° and that of the top is 30°. The height (in meters) of the second tower is