New York (CNN) -- Former New York Mayor Ed Koch has been dead for more than four months, but a mistake on his tombstone likely would have amused him.

Koch was born December 12, 1924, but his tombstone at Trinity Church Cemetery in Upper Manhattan made him appear 18 years younger than he was -- December 12, 1942, was set in stone.

The company responsible for the etchings on the marker became aware of the mistake Monday. The transposed numbers were fixed Tuesday morning using composite granite, according to George Arzt, Koch's former press secretary as mayor and his spokesman until his death.

The birth and death dates were added within the past 10 days, according to an etching company representative.

Koch hired an inscriber after he purchased his tombstone in 2007. He was able to see the engravings were etched as he wished; however, there were no dates at the time, according to Arzt.

"Ed would have loved this attention and called the situation 'ridiculous!' " Arzt told CNN on Tuesday.

Koch was a U.S. congressman from 1968 until he ran for New York mayor in 1977. He served three terms as the city's 105th mayor, from January 1978 to December 1989.

Koch died of congestive heart failure on February 1. He was 88 -- despite what his tombstone temporarily calculated.

Now, provide a numbered list of answers to these questions:

1. In what year did Koch become a congressman?
2. In what year did he run for mayor?
3. How many terms did he serve?
4. Was he the 90th mayor of New York?
5. Which one then?
6. What was the final year he was mayor?
7. How old was he at the time of death?
8. What was the cause of death?
9. On what day did he die?
10. In what year was he born?
11. In what month?
12. Was he initially represented as younger or older than his real age on his tombstone?
13. By how much?
14. On what day did the company become aware of this error?
15. Who was Koch's press secretary?
16. In what year did Koch buy his tombstone?
17. What would did Arzt say Koch would've used to describe the error?
18. What news outlet did Arzt speak with?
19. On what day?
20. What kind of granite was used to fix the tombstone error?
1. 1968
2. 1977
3. three
4. no
5. 105th
6. 1989
7. 88
8. congestive heart failure
9. February 1
10. 1924
11. December
12. younger
13. 18 years
14. Monday
15. George Arzt
16. 2007
17. he would've called the situation 'ridiculous!'
18. CNN
19. Tuesday
20. composite granite