After eating a hearty meal they went to see the Buckingham palace. There, Rachel learned that 18 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 18 visitors on the previous day. 

There were 42 visitors on that day. 

There were 24 more visitors on that day than on the previous day.