Context: Yale has had many financial supporters, but some stand out by the magnitude or timeliness of their contributions. Among those who have made large donations commemorated at the university are: Elihu Yale; Jeremiah Dummer; the Harkness family (Edward, Anna, and William); the Beinecke family (Edwin, Frederick, and Walter); John William Sterling; Payne Whitney; Joseph E. Sheffield, Paul Mellon, Charles B. G. Murphy and William K. Lanman. The Yale Class of 1954, led by Richard Gilder, donated $70 million in commemoration of their 50th reunion. Charles B. Johnson, a 1954 graduate of Yale College, pledged a $250 million gift in 2013 to support of the construction of two new residential colleges.

Question: How much did Charles B. Johnson pledge to Yale in 2013?
Answer: $250 million

Question: How much did the 1954 class donate for their 50th reunion?
Answer: $70 million

Question: Who led the 1954 class in their large donation?
Answer: Richard Gilder

Question: How much didn't Charles B. Johnson pledge to Yale in 2013?
Answer: Unanswerable

Question: How much did Charles B. Johnson pledge to Yale in 2003?
Answer: Unanswerable

Question: How much did the 1945 class donate for their 50th reunion?
Answer: Unanswerable

Question: How much did the 1954 class donate for their 40th reunion?
Answer: Unanswerable

Question: Who led the 1945 class in their large donation?
Answer: Unanswerable