Age Word Problem Solver
Algebra · Linear Equations · Step-by-Step Solution
Pick a problem type, enter the numbers, and get a complete step-by-step algebraic solution with variable definitions, equations, substitution, and answer verification.
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What Are Age Word Problems?
Age word problems are a classic category of algebra problems that appear in school curricula from middle school through high school. They ask you to find the current (or past or future) ages of two or more people, given a set of relationships between those ages. These relationships can be stated as a sum of ages, a difference of ages, a multiple of one age relative to another, or a ratio of ages that changes over time.
Age word problems are popular in school mathematics because they require students to practice a core skill: translating real-world sentences into algebraic equations. Mastering this translation step is the foundation of applied algebra and is tested on SAT, ACT, GRE, GMAT, and competitive entrance examinations worldwide.
How to Solve Age Word Problems: The Standard Method
Every age word problem, regardless of complexity, can be solved with the following five-step method:
- Define variables. Assign a letter (x, y, …) to each unknown age. Write out "let x = Alex's current age" explicitly — this avoids confusion in multi-person problems.
- Translate each condition into an equation. One sentence of the problem typically yields one equation. Work through the problem statement sentence by sentence.
- Solve the system. With two unknowns you need two equations. Use substitution (express one variable from the simpler equation and substitute into the other) or elimination (add or subtract equations to cancel a variable).
- Verify the solution. Plug the values back into every original condition to confirm all of them are satisfied. This step catches arithmetic errors.
- State the answer. Write the conclusion in plain English: "Alex is 20 years old and Blake is 15 years old."
Types of Age Problems
This solver handles four standard problem types plus a free-form custom mode:
| Type | Example condition 1 | Example condition 2 |
|---|---|---|
| Current ages | Alex is 5 years older than Blake | Their ages sum to 35 |
| Future / past ages | In 4 years Alex will be 3 times as old as Blake | Currently Alex + Blake = 24 |
| Ratio problems | Alex : Blake = 3 : 5 today | In 6 years the ratio will be 2 : 3 |
| Three people | C is 8 older than B; B is 5 older than A | Combined age is 54 |
Three Worked Examples
Example 1 — Current ages (difference and sum)
Alex is 5 years older than Blake. Together their ages add up to 35. How old is each person?
Let x = Alex's age, y = Blake's age.
Equation 1 (age difference): x − y = 5
Equation 2 (age sum): x + y = 35
Adding the equations: 2x = 40, so x = 20. Substituting: 20 + y = 35, so y = 15.
Answer: Alex is 20, Blake is 15. Verification: 20 − 15 = 5 ✓ and 20 + 15 = 35 ✓.
Example 2 — Future age (multiple)
In 4 years, Alex will be 3 times as old as Blake. Currently the sum of their ages is 24. Find their current ages.
Let x = Alex's current age, y = Blake's current age.
Equation 1 (future multiple): (x + 4) = 3(y + 4) → x − 3y = 8
Equation 2 (current sum): x + y = 24
Subtracting equation 1 from equation 2: 4y = 16, so y = 4. Then x = 24 − 4 = 20.
Answer: Alex is 20, Blake is 4. Verification: (20 + 4) = 24 = 3 × (4 + 4) = 24 ✓ and 20 + 4 = 24 ✓.
Example 3 — Ratio problem
The ratio of Alex's age to Blake's age is 3 : 5. In 6 years the ratio will be 2 : 3. Find their current ages.
Let x = Alex's age, y = Blake's age.
Equation 1 (current ratio): x / y = 3/5 → 5x − 3y = 0
Equation 2 (future ratio): (x + 6) / (y + 6) = 2/3 → 3x − 2y = −6
From equation 1: x = 3y/5. Substituting: 3(3y/5) − 2y = −6 → 9y/5 − 10y/5 = −6 → −y/5 = −6, so y = 30. Then x = 18.
Answer: Alex is 18, Blake is 30. Verification: 18/30 = 3/5 ✓ and 24/36 = 2/3 ✓.
Common Mistakes to Avoid
- Forgetting to add/subtract the years to both ages. "In 4 years" affects both people's ages: write (x + 4) and (y + 4), not just one.
- Mixing up older/younger direction. If A is older than B, then A − B = difference (positive). Writing B − A gives a negative, leading to a wrong sign in the equation.
- Confusing ratio cross-multiplication. A : B = p : q means A/B = p/q, which cross-multiplies to q · A − p · B = 0. A common error is writing p · A = q · B instead.
- Not verifying. Always substitute your answers back into every original condition. A sign error in step 2 produces an answer that fails verification, catching the mistake before you finalize it.
- Accepting negative ages. A valid solution must have all ages ≥ 0 (and ideally positive). A negative age means a condition was mis-read or entered incorrectly.