June Challenge 2020 Division 2
The Tom and Jerry Game!, Operations on a Tuple, The Delicious Cake, Guessing Game, Chef and Icecream, Covid Sampling (Challenge), Chef and String, Chef and Price Control, Even Matrix
July Challenge 2020 Division 2
Missing a Point, Chef and Strings, Chef and Card Game, Doctor Chef, Chef and Dragon Dens, Chefina and Swaps, LCM Constraints, Ada King
September Challenge 2020 Division 1
Chefina and Swap, Chef and Trump Cards, Find XOR, Ada Matrix
August Cook-Off 2020 Division 1
Red-blue Trees, Polygon Relationship
India