Age Ratio Problem: David and Tom

mediumGrade 5-7age ratio

The Problem

David is 20 years old. David is twice as old as Tom. How old is Tom?

Answer:

10 years old

Key Information

  • David is 20 years old
  • David is twice as old as Tom

Formula

Age₁ = ratio × Age₂

Step-by-Step Solution

1

Identify the relationship

David is twice as old as Tom
2

Set up equation

David's age = 2 × Tom's age
3

Substitute known value

20 = 2 × Tom's age
4

Solve for unknown age

Tom's age = 20 ÷ 2
5

Calculate

20 ÷ 2 = 10
6

Final answer

Tom is 10 years old

Common Mistakes to Avoid

  • Multiplying instead of dividing
  • Using the wrong person's age

Helpful Tips

  • When someone is "twice as old," divide by 2 to find the younger age
  • Check your answer by multiplying back

Real-World Application

Ratio problems help understand proportional relationships between ages.

Related Topics:

ageratiodivisionword problems

Need More Help with Word Problems?

Get personalized 1-on-1 tutoring with expert math tutors. Master word problems, build problem-solving skills, and boost your confidence!

Find Your Math Tutor