Systems of linear equations and inequalities

2000006803

Level: 
C
In the picture, the shaded region corresponds to the set of points that is the solution to one of the given inequalities. Which of the inequality is it?
\[\begin{aligned} y &\leq x+2 \\y &\geq x -2 \end{aligned}\]
\[\begin{aligned} y &\leq x-2 \\y &\geq x+2 \end{aligned}\]
\[\begin{aligned} y &\leq 2x+2 \\y &\geq 2x -2 \end{aligned}\]
\[\begin{aligned} y &\leq 2x-2 \\y &\geq 2x +2 \end{aligned}\]

2000006804

Level: 
C
In the picture, the shaded region corresponds to the set of points that is the solution to one of the given inequalities. Which of the inequalities is it?
\[\begin{aligned} y &\leq x \\y &\geq -x \end{aligned}\]
\[\begin{aligned} y &\leq - x \\y &\geq x \end{aligned}\]
\[\begin{aligned} y &\leq x \\y &\leq -x \end{aligned}\]
\[\begin{aligned} y &\geq x \\y &\geq -x \end{aligned}\]

2010011201

Level: 
C
In the picture, the shaded region corresponds to the set of points that is the solution to one of the given inequalities. Which inequality is it?
\( y \geq -\frac32x+\frac{7}2 \)
\( y \leq -\frac32x+\frac{7}2 \)
\( y > -\frac32x+\frac{7}2 \)
\( y < -\frac32x+\frac{7}2 \)

2010011202

Level: 
C
Students registered for sports camps. For the biking camp registered by \( 12 \) students more than for the boating camp. After some time one of the students switched his registration from the boating camp to the biking camp. Now, there is three times more bikers than boaters. How many students registered originally for the biking camp?
\( 20 \)
\( 21 \)
\( 7 \)
\( 8 \)

9000022901

Level: 
C
An arrow has been shot at the angle \(60^{\circ }\) at the speed \(10\, \mathrm{m}\, \mathrm{s}^{-1}\). Find the time when the height equals to the horizontal distance from the take-off point. Hint: The position is given by the equations \(x = v_{0}t\cdot \cos \alpha \), \(y = v_{0}t\cdot \sin \alpha -\frac{1} {2}gt^{2}\). Use \(g = 10\, \mathrm{m}\, \mathrm{s}^{-2}\) as an acceleration of gravity.
\(\left (\sqrt{3} - 1\right )\, \mathrm{s}\)
\(\left (\sqrt{3} + 1\right )\, \mathrm{s}\)
\(\sqrt{3}\, \mathrm{s}\)
\(\left (\sqrt{2} - 1\right )\, \mathrm{s}\)
\(\left (\sqrt{2} + 1\right )\, \mathrm{s}\)