MathDB
cylindershaped cake for 15 guests

Source: (2021 -) 2022 Dürer Math Competition Regional E1 https://artofproblemsolving.com/community/c1621671_durer_math_competition

November 30, 2022
geometrycombinatorial geometry

Problem Statement

Dorothy organized a party for the birthday of Duck Mom and she also prepared a cylindershaped cake. Since she was originally expecting to have 1515 guests, she divided the top of the cake into this many equal circular sectors, marking where the cuts need to be made. Just for fun Dorothy’s brother Donald split the top of the cake into 1010 equal circular sectors in such a way that some of the radii that he marked coincided with Dorothy’s original markings. Just before the arrival of the guests Douglas cut the cake according to all markings, and then he placed the cake into the fridge. This way they forgot about the cake and only got to eating it when only 66 of them remained. Is it possible for them to divide the cake into 66 equal parts without making any further cuts?