Pipe A alone & pipe B alone can fill the same tank in 5 hours and 4 hours respectively. If the ratio of efficiency of pipe A & B together to that of pipe C alone is 9:2, then find time taken by pipe C alone to fill the same tank?

Directions: The following table represents the percentage marks of four students in six subjects.
Consider the table and answer questions based on it

Who has the highest total marks?

The average of 6 numbers is 20. If a number is removed then average becomes 15. In place of removed number by adding a number 39 the average of new 6 number will be__

A boat running upstream takes 7 hours and 40 minutes to cover a certain distance while it takes 5 hours to cover the same distance downstream. What is the ratio between the speed of the current and speed of the boat respectively? 

ΔABC is an equilateral triangle in which D, E and F are the points on sides BC, AC and AB, respectively, such that AD ⊥ BC, BE ⊥ AC and CF ⊥ AB. Which of the following is true?

The value of $$ {(sec^{2}θ+tanθ\cotθ-tan^{2}θ)}$$

The area  of a circle is 616 sq cm, find its circumference?

If the length and breadth of a rectangle are in the ratio 3:2 and its perimeter is 20 cm, then the area of the rectangle (in cm²) is