After eating a hearty meal they went to see the Buckingham palace. There were 40 paintings in the Buckingham palace. There, Rachel learned that 9 visitors came to the Buckingham palace that day. If there were 8 visitors the previous day How many more visitors visited the Buckingham palace on that day than on the previous day?
There were 40 paintings in the Buckingham palace. 
There, Rachel learned that 9 visitors came to the Buckingham palace that day. 
If there were 8 visitors the previous day, how many more visitors visited the Buckingham palace on that day than on the previous day?

There were 9 visitors on the day Rachel went to see the paintings, and 8 visitors the day before. This means that 1 more visitor came to see the paintings on the day Rachel went than the day before.