A

2000003706

Level: 
A
The length of a rectangle is extended twice its original length. How must its width be changed so that the area of the rectangle remains the same?
the width is reduced to half (of its original width)
the width is increased by half (of its original width)
the width is reduced by a quarter (of its original width)
the width is increased to double (of its original width)

2000003705

Level: 
A
A car going at a speed \(60\,\mathrm{km/h}\) covers the distance from city \(A\) to city \(B\) in \(30\) minutes. If the distance has to be covered in \(20\) minutes, how many times does the driver have to increase the speed when leaving \(A\).
\(1.5\) times
\(1.\overline{3}\) times
\(1.\overline{6}\) times
\(1.2\) times

2000003704

Level: 
A
A car going at a speed \(60\,\mathrm{km/h}\) covers the distance from city \(A\) to city B in \(30\) minutes. If the distance has to be covered in \(20\) minutes, by how many \(\mathrm{km/h}\) must the driver increase the speed when leaving \(A\).
by \(30\,\mathrm{km/h}\)
by \(20\,\mathrm{km/h}\)
by \(40\,\mathrm{km/h}\)
by \(45\,\mathrm{km/h}\)

2000003701

Level: 
A
Group of mountaineers would climb the top of the mountain at an ascent speed of \(400\,\mathrm{m}\) per day in \(10\) days. However, due to the weather, they have to conquer the peak in \(8\) days. How many more meters per day do they have to cover?
\(100\) meters more
\(80\) meters more
\(120\) meters more
\(90\) meters more

2010002110

Level: 
A
There is a part of the function \[ f(x)=\left\{\begin{matrix} &(x+6)^{-2}+2& x \in (-\infty;-5)\setminus\{-6\} \\ &3, & x \in [ -5;-3 ] \\ &1, & x \in (-3;-1) \\ &|x-1|-1& x \in [ -1,\infty)\setminus \{6\}\\ \end{matrix}\right. \] in the picture. Use the graph to determine at how many points of the given interval \([ -8; 7 ]\) is the function \(f\) defined and is not differentiable.
\( 4\)
\(3\)
\(5\)
\(6\)