Travelling at 80km/hr, Praveen reaches his destination at a certain time. He covers 3/5th of his journey in 2/5th at the time. At what speed (in km/hr) should he travel to cover the remaining journey, so as to reach his destination on time? 

Evaluate the following.

sin 25° sin 65° – cos 25° cos 65°.

Two train 120 meters and 160 meters in length are running towards each other on parallel lines at the speed of 70 kmph and 42 kmph respectively. How long will it take to cross each other after they meet?

The average of six consecutive odd numbers is 26. Find the difference between the largest and the smallest of these numbers.

A jeep travels to a place 300 km away at an average speed of 60 km/h and returns at a speed of 30 km/h. What is the average speed (in km/h) for the whole journey?

Given that ( 1² +2²+3²+………..+10²)=385, the value of (2²+4²+6²+……20²) is equal to

If the length of a rectangle increases by 50% and the breadth decreases by 25%, then what will be the percent increase in its area?

A is twice as fast as B and B is thrice as fast as C. The Journey covered by C in  42 minutes will be covered by A in.