In the previous post on Factorials I mentioned that I
needed a factorial algorithm for a Combinations project and the Combinations
project for a Random Walker project.

As you can see in the formula for the number of combinations
of

*n*things taken*r*at a time with no duplications there are three factorials to compute to get to the nCr.
This is a screenshot of the Combinations project. The graphic of the
fruit is to illustrate that if

*n*= 4 (the pear, orange, banana, and strawberry) then there are four combinations (shown in the four rows) when taken 3 at a time. The project first asks for*n*, then*r*and then computes nCr.
The project can be viewed and downloaded by clicking
on this link.

https://scratch.mit.edu/projects/88028765/

A free
document in PDF format describing the coding in more detail can be obtained on
request. Send an email to grandadscience@gmail.com.