For the following questions answer them individually
A man has some hens and some cows. If the total number of heads of hens and cows together is 50 and the nunber of feet of hens and cows together is 142, then the number of cows is
In a class, average height of all students is 'a' cms. Among them, average height of 10 students is 'b' cms and the average height of the remaining students is 'c' cms. Find the number of students in the class. (Here a>c and b>c )
The simplified value of $$\frac{3\sqrt7}{\sqrt5+\sqrt2}-\frac{5\sqrt5}{\sqrt2+\sqrt7}+\frac{2\sqrt2}{\sqrt7+\sqrt5}$$ is
Two circles of radii 17 cm and 8 cm are concentric. The length of a chord of greater circle which touches the smaller circle is
The percentage change of a number when it is first decreased by 10% and then increased by 10% is
Find the angular elevation of the sum when the shadow of a 15m long pole is $$\frac{15}{\sqrt{3}}$$ metres
If 2y cosθ = x sinθ and 2x secθ - y cosecθ = 3 then what is the value of $$x^2 + 4y^2$$ ?
