Time, Work & Distance
Solve classic word problems in seconds.
Core Concepts
These problems often scare students, but simple formulas make them easy!
Time & Work Shortcut
If A takes x days and B takes y days:
Together = (xy) / (x+y)
(Product over Sum).
Speed Conversion
• km/h to m/s: Multiply by 5/18.
• m/s to km/h: Multiply by 18/5.
Solved Examples
Example 1: A in 10 days, B in 15 days
Question: How long together?
• Formula: (A×B) / (A+B).
• (10 × 15) / (10 + 15).
• 150 / 25.
• Answer: 6 days.
Example 2: Convert 72 km/h to m/s
Question: Convert speed.
• Multiply by 5/18.
• 72 × (5/18).
• 18 goes into 72 four times.
• 4 × 5 = 20.
• Answer: 20 m/s.
Example 3: A+B in 6 days, A in 10 days
Question: How long for B alone?
• Formula: (Product) / (Difference).
• (6 × 10) / (10 - 6).
• 60 / 4.
• Answer: 15 days.
