The sum of the digits of a 2digit number is 17. If we add 9 to the number, the new number obtained is a number formed by interchange of the digits. Find the number.
Raghu's tanker can fill a cistern in 4 hours. After half the cistern is filled, three more similar tankers are opened. What is the total time taken to fillthe cistern completely?
If the time increases by 5 years, then simple interest increases by Rs 3000 on a sum of Rs 5000. What is the rate (in percentage) of interest per annum?
In a class of 50 students there are 27 girls. The average weight of these girls is 45 kg and average weight of the full class is 49.6 kgs. What is the average weight of the boys of the class?