A sum of ₹ 3000 yields an interest of ₹ 1080 at 12% per annum simple interest in how many years ?

PQRS is square whose side is 20 cm. By joining opposite vertices of PQRS are get four triangles. What is the sum of the perimeters of the four triangles?

A rectangular grass plot 80 m × 60 m has two roads, each 10 m wide, running in the middle of it; one parallel to length and the other parallel to breadth. Find the cost of gravelling the roads at ₹ 2 per m². 

A solid metallic cylinder of base radius 3 cm. and height 5 cm. is melted to form cones, each of height 1 cm. and base radius 1 mm. The number of cones is -

5-[4-{3-(3-3-6)}] is equal to:

A certain sum of Rs.4200 becomes Rs5523 at 11% p.a simple interest in a certain time. What is the simple interest on the sum of Rs. 4800 at the same rate and in same time period?

If the angle of the elevation of sun is θ and the length of the shadow of a pole of length P is S, then 

If AD, BE and CF are medians of ∆ABC, then which one of the following statements is correct?