A train 150 m. long is running with a speed of 68 km. /hr. In what time will it pass a man who is running at 8 km. /hr. in the same direction in which the train is going?

The simple interest for four years is one fourth of the principal. At the same rate, which amount become Rs.450 total amount in 2 years?

Excluding stoppages, the speed of a bus is 80 kmph and including stoppages, it is 60 kmph. For how many minutes does the bus stop per hour?

An alloy contains a mixture of two metals X and Y in the ratio of 2 : 3. The second alloy contains a mixture of the same metals, X and Y. in the ratio 7 : 3. In what ratio should the first and the second alloys be mixed so as to make a new alloy containing 50% of metal X?

What is compound interest accrued on an amount of Rs 45000 in 2 yr @ 9% per annum ? 

A vertical stick 12 cm long casts a shadow 8 cm long on the ground. At the same time, a tower casts a shadow 40 m long on the ground. The height of the tower is 

The average age of 30 students of a class is 15 years. A 20-year-old student left the class and replaced by two new students, whose age difference is 5 years. If the average age of all students is 15 years, then what will be ratio of young student to elder students.