these probability tree diagram word problems typically fit into middle school to early high school math, depending on the curriculum system. Here’s how they align by grade and unit/topic area: 🇬🇧 UK Curriculum (KS3–KS4 / GCSE) Grade/Year: Year 9–11 (ages 13–16) — KS4 / GCSE level Unit: Probability → subtopic: Tree Diagrams, Combined Events, and Independent/Dependent Probability Usually appears in the GCSE Mathematics syllabus (both Foundation and Higher tiers). 🇺🇸 US Curriculum