Problem on Internet Connection via Wifi and Ethernet Adapter

I have a problem regarding internet connection via wifi and via ethernet adapter using my Dell laptop (model: Inspiron 15-3552)... Actually our internet speed is 3mbps but when i test it I only got 0.2 to 0.3 mbps (via wifi and ethernet adapter) but when I test the speed on other computer (wifi & ethernet adapter) and iPad (wifi) the speed is more than 3mbps.  Can you please advise what are the possible solution?  I really need you help.