ΔABC and ΔDBC are on the same base BC but on opposite sides of it. AD and BC intersect each other O. If AO=a cm, DO=b cm and the area of ΔABC= x cm², then what is the area (in cm²) of ΔDBC?

Find the minimum value of $$ {25 cosec^{2}θ +25sin^{2}θ}$$

In a school 40% of the students play football and 50% play cricket. If 18% of the students neither play football nor cricket, the percentage of the students playing both is:

The sum of all interior angles of a regular polygon is twice the sum of all its exterior angles.  The number of sides of the polygon is

A can do a piece of work in 6 days, B in 10 days and C in 15 days. They jointly complete the work and earn Rs.300. The sum of their wages for 2 days is                                              

A is twice as fast as B and B is thrice as fast as C. The Journey covered by C in  42 minutes will be covered by A in.                                           

The area of a circle is proportional to the square of its radius. A small circle of radius 3 cm is drawn within a larger circle of radius 5 cm. Find the ratio of the difference between the area of the larger circle and that of the smaller circle to the area of the larger circle.

Simplify  $$ ^{3}\sqrt{-2197} × ^{3}\sqrt{{-125}} \ ÷ ^{3}\sqrt{27\over512}$$.