Task description:

Hellow everyone, i have that task. And i have a slight problems with solving it on wolfram calculatior, i need to find a probability for it and investigate a problem in some depth using random numbers and Monte Carlo simulation in excel.
I want to use that formula.
Formulas:

Where $m = 5$, $p = 0.75$, $n = 20$.
I would appreciate any advice on how to analytically solve this problem in excel, with using vba excel code, if it necesary , i.e. expressing that answer in excel can me help simulate problem with different inputs.
Thank you!