In the expansion of
\left(1+x+x^{2}+\cdots+x^{27}\right)\left(1+x+x^{2}+\cdots+x^{14}\right)^{2}
what is the coefficient of x^{28} ?
Answer Choices
A. 195
B. 196
C. 224
D. 378
E. 405
In the expansion of
what is the coefficient of x^{28} ?
Answer Choices
A. 195
B. 196
C. 224
D. 378
E. 405