Problem:
If 1998 is written as a product of two positive integers whose difference is as small as possible, then the difference is
Answer Choices:
A. 8
B. 15
C. 17
D. 47
E. 93
Solution:
The number 1998 has prime factorization 2⋅33⋅3. It has eight factorpairs: 1×1998=2×999=3×666=6×333=9×222=18×111=27×74= 37×54=1998. Among these, the smallest difference is 54−37=17.