Let the girl has 'x' dimes and 'y' quarters.
Consider the following conversions,
[tex]\begin{gathered} 1\text{ dime=10 cents} \\ 1\text{ quarter=25 cents} \\ 1\text{ dollar=100 cents} \end{gathered}[/tex]Given that the number of dimes is six times the number of quarters,
[tex]\begin{gathered} x=6\times y \\ x=6y \end{gathered}[/tex]Also, it is given that the total worth is $37.40,
[tex]\begin{gathered} 10x+25y=37.40\times100 \\ 10(6y)+25y=3740 \\ 60y+25y=3740 \\ 85y=3740 \\ y=44 \end{gathered}[/tex]Then the value of 'x' is obtained as,
[tex]\begin{gathered} x=6(44) \\ x=264 \end{gathered}[/tex]Thus, the girl has 264 dimes and 44 quarters.