A parent is 6 times as old as their child. Together they are 77. How old is each?
The child is 11 and the parent is 66.
How to work it out
- 1
Let x be the child's age. The parent is 6 times as old, so the parent is 6x.
- 2
Together they are 77:
- 3
Combine the x terms and divide:
- 4
The parent is 6 × 11 = 66.
- 5
Check: 11 + 66 = 77 ✓ and 66 = 6 × 11 ✓.
LaTeX source of the formulas on this page
\[ x + 6x = 77\ \Rightarrow\ x = 11 \]
\[ x + 6x = 77 \]
\[ 7x = 77\ \Rightarrow\ x = \frac{77}{7} = 11 \]Questions
How old is the child?
11.
How old is the parent?
66.