Consider that it is necessary to subtract the money Kendra spent on the book and the snack from the total. If x is the total money, and after she bought the book and the snack, she has 4 dollars, then, you have:
![x-(1)/(3)x-(2)/(5)x=4](https://img.qammunity.org/2023/formulas/mathematics/college/r8mm8b48coneyqx9k0e7sf1ie6evc71upc.png)
To determine the value of x, it is necessary to solve the previous equation. Multiply by the least common multiple to cancel out the denominators of the fractions. The least common multiple is 15:
![\begin{gathered} 15x-5x-6x=60 \\ 4x=60 \\ x=(60)/(4)=15 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/kwho61tdc6nxgadoy7n19vif7fol5bb1df.png)
Hence, the total amount of allowance Kendra had was 15 dollars