Cathy is drawing flowers. The first one is red, the next one blue, the one after it yellow, the fourth one pink, and then again red, blue, yellow, pink, and so on, in the same order. What color will be the $19$\textsuperscript{th}~flower? (Adapted from 2003 Math Kangaroo Problem, Level 3-4, Question \#4) 
Overseas Competition->Knowledge Point->Word Problem Modules->Periodic Problems->Periodic Problems of Basic Permutation
$19\div4=4R3$, so the $19$\textsuperscript{th} flower is yellow. 