Quantitative Aptitude - Arithmetic Ability Questions

In what time will a 100 metre long train running with a speed of 50 km/hr cross a pillar?

P and Q can do a project in 20 and 12 days respectively. In how many days can they complete 40% of the project if they work together?

The average of 21 numbers is 12. The average of the first 11 numbers is 9 and the average of the last 11 numbers is 15. What is the value of the middle number?

What is the average of all numbers between 8 and 74 which are divisible by 7?

A can do a work in 16 days and B in 20 days. If they work on it together for 8 days, then what fraction of work is left?

A trader buys 500 kgs of cotton for Rs 9,000. 10% of this cotton is spoiled due to rain. At what rate (Rs/Kg) should he sell the rest to earn 10% profit?

The price of an article is cut by 9%, to restore to its original value, the new price must be increased by

If a sum of money deposited in a bank at simple interest is doubled in 6 years, then after 12 years, the amount will be