Answer:
15 two-point questions and 5 four-point questions.
Explanation:
Let x represent number of two-points questions and y represent number of four-points questions.
We have been given that Janice wants to create a test containing 20 questions. We can represent this information in an equation as:
![x+y=20...(1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/sjccsm82oxzvsabximuprwg65bkjzaiczd.png)
Since all questions are worth 50 points. We can represent this information in an equation as:
![2x+4y=50...(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/roqu13g5t70nr7a507xjfuav2yvo46rcio.png)
From equation (1), we will get:
![x=20-y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b5i90rpgd6i2kn6h1l4kyqepn5l98laym3.png)
Upon substituting this value in equation (2), we will get:
![2(20-y)+4y=50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wuua8hhciv9xufsh0m30xy3z890n559equ.png)
![40-2y+4y=50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kfm7l5c4e07xxtjonktukjmbrduosrpypg.png)
![40+2y=50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/rb52oh4ue9lyedciup05l6tjxxoscl9f3z.png)
![40-40+2y=50-40](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jl6vuxxj7qegzxfbacimhviko0s88ed571.png)
![2y=10](https://img.qammunity.org/2020/formulas/mathematics/middle-school/hska5gdcqqcoadknye8qoqt9slokvp3fie.png)
![(2y)/(2)=(10)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/sa96390d9plkrams13bzf6rpq66kzq0pkx.png)
![y=5](https://img.qammunity.org/2020/formulas/mathematics/high-school/vz87m1ge16cb4tz4pxuo69xmt9ogjrotw7.png)
Therefore, there are 5 questions that are worth 4 points each.
Now, we will substitute
in equation (1) to solve for x.
![x+5=20](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fpdo3u4257b4hcgq379j0z4l9se8hs586p.png)
![x+5-5=20-5](https://img.qammunity.org/2020/formulas/mathematics/middle-school/3p537gyk67znpn3vrg289iop8umf7g3ngb.png)
![x=15](https://img.qammunity.org/2020/formulas/mathematics/high-school/x785klezqcvapj8xmzkxavn9qrwqaoskne.png)
Therefore, there are 15 questions that are worth 2 points each.