usb keyboard some keys do not work macbook pro OS X yosmite 10.10.4
Purchased a usb extended keyboard from apple store on advice for apple assistant. Some of the keys do not work when i use it. The keys are 1, 4, 7 and k. there could be others. I have tried all suggestions I have found relating to this and none have helped. Very frustrated as I have tried for a number of days to get this to work. Frustrated......especially since I was advised to purchase the keyboard. Can someone please help.
Not sure if posting in correct area, I just want support help
MacBook Pro (15-inch Mid 2012), OS X Yosemite (10.10.4)