After eating a hearty meal they went to see the Buckingham palace. There, Rachel learned that 8 visitors came to the Buckingham palace on the previous day. If there were 42 visitors on that day How many more visitors visited the Buckingham palace on that day than on the previous day?
There were 42 visitors on that day. 
8 visitors came to the Buckingham palace on the previous day. 

So, we need to find the difference between 42 and 8, which is 34. 

Therefore, 34 more visitors visited the Buckingham palace on that day than on the previous day.