Li Ling had some $2 notes and Anna had some $5 notes. After Li Ling
used of her notes and Anna used of her notes, they had the same
number of notes left. If they had $315 altogether in the end, how much
money did Li Ling have at first?

When a researcher debriefs her participants, she: provides a detailed explanation of the study. removes their undergarments. tells them they can stop taking part at any time. provides an detailed explanation of the study, and tells them they can stop taking part at any time.