NUMBER SYSTEM - SIMPLE PROBLEMS ONLINE

I am giving below links for number system problems.  pl attend.
http://prepare4quiz.appspot.com/practice/bankpo/quantitative/numbersystem

http://prepare4quiz.appspot.com/practice/bankpo/quantitative/hcflcm

-- http://prepare4quiz.appspot.com/practice/bankpo/quantitative/hcflcm