I have physics electrostatics and current electricity book. I entered the coupon code but my test series of the same chapter is locked. I entered the code again it says that coupon already used and still the test is last locked
OK what's the unused code????
But if we enter the coupon code we can access all the chapters of that book, but that's not the case with only electrostatics and electric current.
Ya cengage provides free access to some chapters on the app, if you want to retry , tell me I have unused code