In what time will ₹ 72 become ₹ 81 at $$6{1\over4}$$ % per annum simple interest?

There is 80% increase in an amount in 8 years at simple interest. What will be the compound interest on Rs. 15,000 after 3 years at the same rate of interest?

The perimeter of a square with diagonal 29√2 cm is equal to the perimeter of a rectangle. Find the area of the rectangle if the length of the rectangle is 8 cm more than the breadth of the rectangle?

What is the height of a solid right circular cylinder whose radius is 3 cm and total surface area is 60 πcm² ?

In the given question, two equations numbered l and II are given. Solve both the equations and mark the appropriate answer.

I. x² - 25x + 156 = 0

II. y²- 20y + 96 = 0

Two towns P and Q are 170 km apart, a train starts at 9 a.m. from P towards Q at a speed of 40 km/hr, at 11 a.m. another train starts from Q towards P at a speed of 50 km/hr. When will the two trains meet?

If $${secθ+tanθ\over secθ-tanθ}={5\over 3}$$ then sinθ is equal to ;

There are two groups A and B of a class, consisting of 42 and 28 students respectively. If the average weight of group A is 25 kg and that of group B is 40 kg, find the average weight of the whole class.