First they tried bolding the words more than the ball to make this clause more salient. ("bolding" betyder betona). "At this point they [Spunt and Frederick] completely gave up and just flat out added “HINT: 10 cents is not the answer.” This worked reasonably well, though there was still a hard core of 13% who persisted in writing down 'ten cents'.
R. Schaeffer, B. Miranda, and S. Koyejo. Proceedings of the 37th International Conference on Neural Information Processing Systems, page 55565--55581. Red Hook, NY, USA, Curran Associates Inc., (Dec 10, 2023)