\(20\times20\) Lattice Paths, No Need For A Computer Right?
Starting in the top left corner of a \(2\times2\) grid made out of single \(1\times1\) squares, and only being able to move to the right and down, there are exactly 6 routes to the bottom right corner.
How many such routes are there in a \(20\times20\) grid?
You may use a calculator for the final step of your calculation.
Hint: Pascal's triangle.