The expression n! means the product of the positive integers from 1 to n. For example, 5!=1×2×3×4×5. The value of 6!−4! is
(A) 2 (B) 18 (C) 30 (D) 716 (E) 696
Want a route through all this instead of an archive? The track
puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.
Source: CEMC, University of Waterloo,
licensed CC-BY-NC-4.0.
Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.