A copper wire is bent in the shape of a square of area 81 cm². If the same wire is bent in the form of a semicircle, the radius (in cm) of the semicircle is (take π=22/7 ) 

Two parallel chords are drawn in a circle of diameter 30 cm. The length of one chord is 24 cm and the distance between the two chords is 21 cm. The length of the other chord is 30 cm 

A person bought some rice and wheat for ₹ 380. The ratio of weight of rice and wheat is 4 : 3 and the price of equal amount of rice and wheat is in the ratio 5 : 6. The rice was bought of worth 

Profit after selling a commodity for 524 is the same as loss after selling it for Rs. 452. The cost price of the commodity is 

If $$x=(\sqrt2+1)^{1\over3} $$, the value of $$(x^3-{1\over {x^3}}) $$ is

The value of $${\sqrt{40+\sqrt{9\sqrt{81}}} }$$ is

The area of a triangle with vertices A (0, 8), O (0, 0), and B (5, 0) is :

A water reservoir has two inlets and one outlet. Through the inlet it can be filled in 3 hours and 3 hours 45 minutes respectively. It can be emptied completely in 1 hour by the outlet. If the two inlets are opened at 01 : 00 pm and 02 : 00 pm respectively and the outlet at 03 : 00 pm then it will be emptied at :