What will be the least number which when doubled with be exactly divisible by 12, 18, 21 and 30 ?

A train 800 meters long is running at a speed of 78 km/hr . If it crosses a tunnel in 1 minute, then the lengt...

If 4 (A's capital) = 6 (B's capital)=10(C's capital), then out of a profit of TK. 4650, C will receive :

How many times in a day, are the hands of a cock in straight line but opposite in direction ?

Tow numbers A and B are such that the sum of 5% of A and 4%of B is two-third of the sum of 6% of A and 8%of B....

If the number 5 * 2 is divisible by 6, then * = ?

3 pumps , working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty t...