Unresponsive Touchpad in Dell Inspiron 3551

Just bought this laptop from a friend and installed Ubuntu 16.04 LTS.

The installation went well until it booted up and I saw that my touchpad is not working. It used to work fine in my friend's Windows as well!

Here's my xinput:

⎡ Virtual core pointer                          id=2    [master pointer  (3)]  
⎜   ↳ Virtual core XTEST pointer                    id=4    [slave  pointer  (2)]  
⎜   ↳ 2.4GHz RF  KEYBOARD  AND  MOUSE               id=11   [slave  pointer  (2)]  
⎜   ↳ DLL06AB:00 06CB:78F1                          id=13   [slave  pointer  (2)]  
⎜   ↳ SynPS/2 Synaptics TouchPad                    id=15   [slave  pointer  (2)]  
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]  
    ↳ Virtual core XTEST keyboard                   id=5    [slave  keyboard (3)]  
    ↳ Power Button                                  id=6    [slave  keyboard (3)]  
    ↳ Video Bus                                     id=7    [slave  keyboard (3)]  
    ↳ Power Button                                  id=8    [slave  keyboard (3)]  
    ↳ Sleep Button                                  id=9    [slave  keyboard (3)]  
    ↳ 2.4GHz RF  KEYBOARD  AND  MOUSE               id=10   [slave  keyboard (3)]  
    ↳ Integrated_Webcam_HD                          id=12   [slave  keyboard (3)]  
    ↳ AT Translated Set 2 keyboard                  id=14   [slave  keyboard (3)]  
    ↳ Dell WMI hotkeys                              id=16   [slave  keyboard (3)]  

I really want this to start working as my work at JustDoc is totally dependent on this and my productivity has gone down without a working trackpad.

P.S. I'm totally new to Ubuntu. TIA.