The length of a hollow thick cylindrical metallic pipe is 6 cm and its total surface area including the surface at the ends is 98π sq. cm. If the outer diameter is 8 cm, then the inner diameter in cm is 

The least number which must be subtracted from 2361 to make it a perfect square is

If (x + k ) is the common factor of x² + ax + b and x² + cx + d , then what is k equal to ?

What is the highest common factor of 2x³ + x² -x -2 and 3x³- 2x² + x - 2 ? 

A and B are 2 cities 60 Km. apart. Two men P and Q start together to walk from A to B. Speed of P is 4 Km / hr. less than that of Q. Q reaches the city B and return back . He meets P at 12 Km away from city B. What is the speed of P? 

A and B started business with the initial investment in the ratio 12:11 and their profit in the business were 4x and x respectively. If A invested the money for 11/12 year, then B invested the money for?

x is a five - digit number. The digit in ten thousand's place is 1. The number formed by its digits in unit's and ten's places is divisible by 4. The sum of all the digits is divisible by 3 . If 5 and 7 also divide x, then x will be: 

 If $$ {x\over y}={y\over w}$$ then what is the value of (xy+zw).