PQR is a triangle right-angled at Q. If X and Y are the mid-points of the sides PQ and QR respectively, then which one of the following is not correct ?

A sphere and a cube have same surface area. What is the ratio of the square of volume of the sphere to the square of volume of the cube?

A cardboard sheet in the form of a circular sector of radius 30 cm and central angle 144⁰ is folded to make a cone. What is the radius of the cone ?

Which one of the following numbers is divisible by 11?

Out of 105 students taking an examination for English and Mathematics, 80 students pass in English, 75 students pass in Mathematics and 10 students fail in both the subjects. How many students pass in only one subject?

In a class of 49 students, the ratio of girls to boys is 4 : 3. If 4 girls leave the class, the ratio of girls to boys would be

If an amount of Rs. 800 is distributed between Ravi, Mohan and Govind in the proportions 2: 5: 3, then the sum of the shares of Mohan and Govind, is:

A person invested one-fourth of the sum of Rs. 25,000 at a certain rate of simple interest and the rest at 4% p.a. higher rate. If the total interest received for 2 years is Rs. 4,125, what is the rate at which the second sum was invested?

An automobile financer claims to be lending money at simple interest, but he includes the interest every six months for calculating the principal. If he is charging an interest at the rate of 10%, the effective rate of interest becomes

A cube is coloured red on all the sides. It is then cut into 64 smaller equal cubes. These cubes are now separated and one cube is picked at random. What is the probability that the cube picked is not coloured on any surface?