Can you help me with this question please

Given:
Amount = £399
Ratio of amount gets Ann to Bill = 2 : 9
Chloe and Dave get 2.5 times the amount Ann gets.
To find:
The amount of money that Bill gets.
Solution:
Let Ann, Bill, Chloe and Dave gets 2x, 9x, 2.5 × 2x and 2.5 × 2x.
[tex]2x + 9x + (2.5 \times 2x) + (2.5 \times 2x) = 399[/tex]
[tex]2x + 9x + 5x + 5x = 399[/tex]
[tex]21x = 399[/tex]
Divide by 21 on both sides.
[tex]$\frac{21x}{21} =\frac{399}{21}[/tex]
x = 19
Amount that Bill gets = 9x
= 9 × 19
= 171
The amount of money that Bill gets £171.