BPP Practice and revision kit- 6.22- pg 27

Hello. I'm abit confused by this question. I understand the concept of valuing closing inventory using weighted average, but have trouble understanding this question. @A wholesaler had opening inventory of 300 units of product Emm valued at $25 per unit at the beginning of Jan. Folling receipts and sales were recorded in Jan Date Issues 2 Jan 250 12 Jan 400 21 Jan 200 29 Jan 75 Purchase cost of receipts was $25.75 per unit. Using weighted avg, calculate the value of closing stock. ---- My question is this: How do you which were sales and which were receipts by just looking at the question. I assumed that this was the total inventory level, so must have been an issue of sale of 50 units on 2nd, purchased 150 on 12th, but that was wrong. Can you please help? How am I reading the question wrong? Thanks.