A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?

The volume of a cylinder having base radius 3 cm is 396 cm\(^3\). Find its curved surface area (in cm\(^2\)). (Use \(\pi = \frac{22}{7}\))

A train running at the speed of 80 km/h crosses a 350 m long tunnel in 36 seconds. The length of the train (in m) is

In a square, lengths of the diagonals are \((4k + 6)\) cm and \((7k - 3)\) cm. The area of the square (in cm\(^2\)) is :

If the mean of \(3, 4, 9, 2k, 10, 8, 6\) and \((k + 6)\) is 8, and mode of \(2, 2, 3, 2p, (2p + 1), 4, 4, 5\) and 6 (\(p\) is a natural number) is 4, then the value of \((k - 2p)\) is :

A certain sum becomes ₹2,356 in 3 years and ₹2660 in 5 years on simple interest. The value of sum is:

In triangle ABC, points D and E are on AB and AC respectively such that DE is parallel to BC. If AD = 6 cm, DB = 4 cm, AE = 9 cm, then the length of EC (in cm) is

An item is sold for ₹504 after allowing 20% discount and still a profit of 5% has been earned. The marked price is how much more than the cost price?

A sum of money becomes thrice of itself in 20 years. Find the simple interest rate per annum?