I have heard this question a lot in my last 13 years of teaching CPR and First Aid. While I tend to teach CPR classes in Denver, this question is one that is applicable to anyplace in the world.
While the ideal answer is that you should be trained in both CPR and First Aid, time and money constraints often get in the way. In the case of businesses, it is often a regulatory issue. Often a business just wants to provide safety training to their employees.
However, the probability of coming across a situation that requires first aid is significantly higher than needing to provide CPR. From seizures to overdose, there are literally hundreds of different types of injury and medical emergencies a person can run into.
For instance, one client of mine routinely deals with head trauma, seizures, diabetic emergencies and choking. In the last 10 years as my client, they have not had a single cpr related incident.
The next time that you think about taking a cpr class, think twice about it and perhaps contemplate first aid training instead.