If x is real then the minimum value of (x²-x-1) is :

In a class, there are ' z ' students. Out of them ‘x’ are boys. What part of the class is composed of girls? 

If $$ {sin\ {θ}}={1\over {\sqrt{2}}}$$ then (tanθ+cosθ)=?

Travelling at 80km/hr, Praveen reaches his destination at a certain time. He covers 3/5th of his journey in 2/5th at the time. At what speed (in km/hr) should he travel to cover the remaining journey, so as to reach his destination on time? 

Two numbers, of which the first number is 200% of the second number. If the sum of the squares of the first number and the cube of the second number is 5 times the product of both numbers, find the difference between the two numbers?

A straight line parallel to the base QR of the ∆PQR intersect PQ and PR at the points S and T respectively. If the area of the ∆PQT be 36 cm² then area of the ∆PRS is:

The distance between the centers of two circles having radii 4.5 cm. and 3.5 cm. respectively is 10 cm. What is the length of the transverse common tangent of these circles?

A boat goes 10kms an hour in still water, but takes twice as much time in going the same distance against the current. The speed of the current (in km/hr) is