How can we make money by doing simple task online

You can earn money by doing simple task online for this join http://www.mturk.com and ready following tips carefully.

some tips to make money on MTURK
In MTURK Task are termed as HIT(Human Intelligence Task)
If you are new to mturk, then start with the HITs that are easy and a vailable most. The idea here is to increase your HIT approval rate(%).
once you have high approval rate, you can go for somewhat difficult ones and earn more. Always maintain a high approval rate as quality Requesters mostly maintain HITs approval rate(%) high to only let the best worker work on their HITs.

Make sure that"show all details' is clicked when working on HITS in all open HITS brower window, this will aid you in seeing the essential requirements and qualification for HIT.