Each Tuesday, a bus makes its first stop at Gauss Public Library at 1 p.m. It continues to stop at the library every 20 minutes. Its last stop is at 6 p.m. What is the total number of times that the bus stops at Gauss Public Library on a Tuesday?
(A) 16
(B) 14
(C) 10
(D) 20
(E) 18
The bus stops at the library at 1:00 p.m., 1:20 p.m., and 1:40 p.m..

The bus stops at the library at 2:00 p.m., 2:20 p.m., and 2:40 p.m..

Similarly, the bus stops at the library at $x: 00$ p.m., $x: 20$ p.m., and $x: 40$ p.m. for $x=3,4,5$.

Finally, the bus stops at 6:00 p.m..

In total, the bus stops at the library $3 \times 5+1=16$ times.

ANswer: (A)

#