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

A gun is fired at a distance of 1.7 km from Ram and he hears the sound after 25 seconds. The speed of sound in meter per second is

If A is equal to 20% of B and B is equal to 25% of C; then what percent of C is equal to A

A store sells a watch for a profit of 25% of the cost. Then the percentage of profit against selling price is

The average of a,b,c is 20 and that of b,c,d is 25; if d=30, then the value of a is