A parent is 4 times as old as their child. Together they are 50. How old is each?
The child is 10 and the parent is 40.
How to work it out
- 1
Let x be the child's age. The parent is 4 times as old, so the parent is 4x.
- 2
Together they are 50:
- 3
Combine the x terms and divide:
- 4
The parent is 4 × 10 = 40.
- 5
Check: 10 + 40 = 50 ✓ and 40 = 4 × 10 ✓.
LaTeX source of the formulas on this page
\[ x + 4x = 50\ \Rightarrow\ x = 10 \]
\[ x + 4x = 50 \]
\[ 5x = 50\ \Rightarrow\ x = \frac{50}{5} = 10 \]Questions
How old is the child?
10.
How old is the parent?
40.