The average of some natural numbers is 15. If 30 is added to first number and 5 is subtracted from the last number, the average become 17.5. then the numbers of natural numbers is :

The radius of the incircle of a triangle is 2 cm. If the area of the triangle is 6 cm2. Then its perimeter is -

The circumference of a circle is 792 m. What will be its radius?

The cost of levelling a ground in rectangular shape for a proposed garden at 80 paise per square meter is Rs.132 and the cost of fencing the same along its perimeter is Rs.78 at Rs.1.50 per meter. If the garden is extended in rectangular shape with its sides as cubes of the originally proposed garden, what will be the perimeter of the garden after extension?

If 4tanθ=3,the  value of $$ \left({4sinθ-2cosθ\over4sinθ+2cosθ}\right) $$ is:-

If one root of the equation Ax²+Bx+C = 0 is two and a half times the others, then which of the following is TRUE? 

Two boats are traveling with speeds of 36 km/hr and 54 km/hr respectively towards each other. What is the distance (in meters) between the two boats one second before they collide?

A goods train 350 m long passes through a tunnel of length 1250 m in 80 seconds. What is the speed of the train?