43 campers went rowing and 11 campers went hiking in the morning. 14 campers went rowing in the afternoon. How many campers went rowing and hiking in all?
43 campers went rowing in the morning.
14 campers went rowing in the afternoon.
That means that a total of 57 campers went rowing. 
11 campers went hiking in the morning. 
That means that a total of 11 campers went hiking. 
Now we need to find out how many campers went rowing and hiking. 
There are two ways to do this: 
1) We can add the total number of campers who went rowing and the total number of campers who went hiking. 57 + 11 = 68. So 68 campers went rowing and hiking. 
2) We can subtract the total number of campers who did not go rowing and hiking from the total number of campers who went rowing or hiking. 43 + 14 + 11 = 68. So 68 - 43 - 14 = 11. So 11 campers went rowing and hiking.