Question

In a certain game, a player can solve easy or hard puzzles. A player earns 30 points for solving an easy puzzle and 60 points for solving a hard puzzle. Tina solved a total of 50 puzzles playing this game, earning 1,950 points in all. How many hard puzzles did Tina solve?10
15
25
35

Answer 1

Answer:  Second option.

Step-by-step explanation:

Let be "e" the number of easy puzzles Tina solved and "h"  the number of hard puzzles Tina solved.

Set up a system of equations:

$\left \{ {{e+h=50} \atop {30e+60h=1,950 }} \right.$

You can use the Eliminationn Method to solve this system of equations:

• Multiply the first equation by -30.
• Add the equations.
• Solve for "h".

Therefore, through this proccedure, you get:

$\left \{ {-30e-30h=-1,500} \atop {30e+60h=1,950 }} \right.\\.........................\\30h=450\\\\h=\frac{450}{30} \\\\h=15$