A parent is 5 times as old as their child. Together they are 84. How old is each?
The child is 14 and the parent is 70.
How to work it out
- 1
Let x be the child's age. The parent is 5 times as old, so the parent is 5x.
- 2
Together they are 84:
- 3
Combine the x terms and divide:
- 4
The parent is 5 × 14 = 70.
- 5
Check: 14 + 70 = 84 ✓ and 70 = 5 × 14 ✓.
LaTeX source of the formulas on this page
\[ x + 5x = 84\ \Rightarrow\ x = 14 \]
\[ x + 5x = 84 \]
\[ 6x = 84\ \Rightarrow\ x = \frac{84}{6} = 14 \]Questions
How old is the child?
14.
How old is the parent?
70.