GAUSS7 2005 Problem 17

Past Contests GAUSS7 2005
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1

The symbol gauss7 2005 7is evaluated as 3\times6+4\times5=38. If gauss7 2005 7b is evaluated as 16, then the number that should be placed in the empty space is

Answer Choices
A. 1
B. 2
C. 3
D. 4
E. 5