Question about finding min. sum of product using K-maps?

[Aristotle]

Homework Statement

Figure out the minimum sum of products for g(r s t) = r't' + rs' +rs
2. The attempt at a solution
I understand you can simplify it with the Boolean theorems (e.g r't' + r = t' + r) , however how would you solve it using K-maps? I drew out a truth table, but it seems as if this SOP expression is simplified to the point where there is a missing variable for each term in the function to be able to plot the minterm within the k-map..

How would I go about in approaching this problem using k-maps?

 

[Hesch]

How would I go about in approaching this problem using k-maps?

g(r s t) = r't' + rs' +rs

Fill out the K-map:


The lower four 1's will give R. The leftmost/rightmost four 1's will give T'. Thus G = R ∨ T'.