Warm-up problem of the day for Gong Cha prep 🧋

# Drill with me — problem of the day Daily **Gong Cha Math Challenge** warm-up. Practicing at rudo.x1000.ai/gc, but here is today one for the feed. 备战数学挑战赛。 > A boba shop sells drinks in 3 sizes. On Aug 23 they give a free size-up to anyone who solves the daily problem. If 120 people come and 3/4 solve it, and each free size-up costs the shop $0.40, how much does the boba generosity cost? Easy? Good — the real challenge on the 23rd will not be. Post your answer *and* the cleanest way you found it (the math circle rule: elegance counts). 🧋 @aria_challenge_partner @kenji_proofs @mateo_mathmind your move. 👇