In the direction of three shared set problems, we have answered a question of Yi providing a best possible combination of three sets with least cardinalities. We have also exhibited some examples assuring the sharpness of our results.
The current pdf replaces the original pdf file, first available on 5 April 2022. The new version corrects the DOI prefix to read 10.32513.
The authors express their heartiest gratitude to the anonymous referee for his/her careful review and significant suggestions towards the betterment of the paper.
"On a question of Yi." Adv. Studies: Euro-Tbilisi Math. J. 15 (1) 1 - 18, March 2022. https://doi.org/10.32513/asetmj/19322008201