To simplify the expression \(\frac{t^{400}}{t^{100}}\) using the Quotient Rule of Integer Exponents, we can apply the rule which states:
\[ \frac{a^m}{a^n} = a^{m-n} \]
In this case, \(a = t\), \(m = 400\), and \(n = 100\). Therefore, we subtract the exponents:
\[ \frac{t^{400}}{t^{100}} = t^{400 - 100} = t^{300} \]
Thus, the simplified expression is:
\[ t^{300} \]