49 campers went rowing and 15 campers went hiking in the morning. 1 campers went rowing in the afternoon. How many campers went rowing and hiking in all?
How many campers went rowing in all? 
There were 49 campers rowing in the morning, and 1 camper rowing in the afternoon. So, in all, 50 campers went rowing. 

How many campers went hiking in all? 
There were 15 campers hiking in the morning. So, in all, 15 campers went hiking. 

How many campers went rowing and hiking in all? 
There were 50 campers who went rowing, and 15 campers who went hiking. So, in all, 65 campers went rowing and hiking.