Answer: Tine solved 15 hard puzzles.
Step-by-step explanation:
Let x be the number of easy puzzles and y be the number of hard puzzels.
Given : A player earns 30 points for solving an easy puzzles and 60 points for solving a hard puzzled.
Tina solved a total of 50 Puzzles playing this game, earning 1950 points in all.
Then system of equations for above description:
![x+y=50--------(1)\\30x+60y=1950---------(2)](https://tex.z-dn.net/?f=x%2By%3D50--------%281%29%5C%5C30x%2B60y%3D1950---------%282%29)
Multiply 60 in equation (1), we get
![60x+60y=3000-----(3)](https://tex.z-dn.net/?f=60x%2B60y%3D3000-----%283%29)
Subtract equation (2) from (3), we get
![30x=1050\\\\\Rightarrow\ x=\dfrac{1050}{30}=35](https://tex.z-dn.net/?f=30x%3D1050%5C%5C%5C%5C%5CRightarrow%5C%20x%3D%5Cdfrac%7B1050%7D%7B30%7D%3D35)
Put x=-35 in (1), we get
![35+y=50\\\\\Rightarrow\ y=50-35=15](https://tex.z-dn.net/?f=35%2By%3D50%5C%5C%5C%5C%5CRightarrow%5C%20y%3D50-35%3D15)
Hence, Tine solved 15 hard puzzles.