SOLUTION:
Step 1:
In this question, we are given the following:
Step 2:
The details of the solution are as follows:
Let the number of advance tickets sold be p and
Let the number of same-day tickets sold be q, such that:
![\begin{gathered} 20\text{ p + 40 q = 1400 -- equation 1} \\ p\text{ + q = 45 ----- equation 2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/7mroeni81flu1mu86wuub0jj07lcrxt4o4.png)
![equation\text{ 2 x 20 = 20 p + 20 q = 900 -- equation 3}](https://img.qammunity.org/2023/formulas/mathematics/college/uevt87wyb5wjxvklmud6krar8dpdhzjrmu.png)
![\begin{gathered} equation\text{ 1 minus equation 3, we have that:} \\ 40\text{ q - 20 q = 1400 - 900} \\ 20\text{ q = 500} \\ Divide\text{ both sides by 20, we have that:} \\ q\text{ =}(500)/(20)=\text{ 25} \\ q\text{ = 25} \\ since\text{ q = 25, put the value of q in equation 1:} \\ p\text{ + q = 45} \\ p\text{ + 25 = 45} \\ p\text{ = 45 - 25} \\ p\text{ = 20} \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/10qkqhlku1k29megw6ekgd4l58j26dzamc.png)
CONCLUSION:
The number of advance tickets sold = 20
The number of same-day tickets sold = 25