Can You Solve This Seemingly Simple Math Problem That Baffled Adults?

The Ruler Problem Setup

• 📦 A box contains three staggered rulers: yellow, blue, and green, within an 18 cm space.
• 📏 Specific overlaps are given: the blue ruler protrudes 3 cm past the yellow, and the green starts 2 cm to the right of the blue.
• ⚖️ A key piece of information is that the blue ruler is exactly 1 cm shorter than the green ruler.

Initial Complex Solution Approach

• 🧠 The presenter's first attempt involved setting the green ruler's length to 'x' and deriving the blue ruler's length as 'x-1'.
• 🧮 Through a series of subtractions and algebraic manipulations involving the given overlaps (3 cm and 2 cm), the presenter calculated the remaining distance on the right side to be 3 cm.
• 💡 This led to an equation: Yellow Ruler Length + 3 cm + 3 cm = 18 cm, resulting in a yellow ruler length of 12 cm.

A More Direct Algebraic Method

• ➡️ This approach traces the measurements sequentially across the box: Yellow Ruler + 3 cm - Blue Ruler + 2 cm + Green Ruler.
• 🧩 Using the relationship that Green Ruler = Blue Ruler + 1 cm, the equation becomes: Yellow Ruler + 3 cm + 2 cm + 1 cm = 18 cm.
• ✅ Simplifying this, Yellow Ruler + 6 cm = 18 cm, directly yielding a yellow ruler length of 12 cm.

The Intended Simpler Solution

• ↔️ This method involves visualizing sliding the blue ruler to align with the green ruler.
• 📏 If the blue ruler were slid 2 cm to the right to align its start with the green ruler's start, the 1 cm difference in length would be exposed.
• 🧩 By considering the overlaps and the 1 cm difference, the total length can be represented as: Yellow Ruler + 3 cm + 2 cm + 1 cm = 18 cm.
• 🎯 This again simplifies to Yellow Ruler + 6 cm = 18 cm, confirming the yellow ruler's length is 12 cm.