The radii of two concentric circles are 17 cm and 25 cm. a straight line PQRS intersects the larger circle at the points P and S and intersects the smaller circle at the points Q and R. If QR = 16 cm, then the length (in cm.) of PS is 

ABC is a triangle in which DE || BC and AD: DB = 5: 4. Then DE: BC is

ABCD is a cyclic quadrilateral. AB and DC when produced meet at P, If PA 8 cm, PB = 6, PC = 4 cm, then the length (in cm) of PD is

If p : q : r = 1: 2: 4, then $$\sqrt{5p^{2}+q^{2}+r^{2}}$$ is equal to 

The ratio of the first and second class train fares between two stations is 3: 1 and that of the numbers of passengers travelling between the two stations by first and second classes is 1: 50. If on a particular day. 1,325 are collected from passengers travelling between the two stations. Then the amount collected from the second class passengers is

 The monthly income of two persons are in the ratio 2: 3 and their monthly expenses are in the ratio 5: 9. If each of themn saves ₹ 600 per month, then their monthly incomes are

The annual income of A and B Aare in the ratio 4: 3 and the ratio a of their expenditures is 3 : 2. If each of them saves ₹ 600 in the year, the annual income of A is 

A discount of 16% on the marked price of a book enables a man to buy a pen that costs? 80. How much did he pay for the book?