B

2010013404

Level: 
B
Find the solution set of the following equation in the set of complex numbers. \[ x^{3} - 8 = 0 \]
\(\left\{2;\ -1 - \mathrm{i}\sqrt{3};\ -1 +\mathrm{i}\sqrt{3}\right\}\)
\(\left\{2;\ 1 - \mathrm{i}\sqrt{3};\ 1 +\mathrm{i}\sqrt{3}\right\}\)
\(\left\{2;\ 1 - \mathrm{i}\sqrt{3}\right\}\)
\(\left\{2;\ - 1 + \mathrm{i}\sqrt{3}\right\}\)

2010013402

Level: 
B
Solve the following equation in the set of complex numbers. (Solve the equation by substitution.) \[ (3x + 2)^4 - 81 = 0 \]
\( \left\{-\frac53;\frac13;-\frac23+\mathrm{i} ;-\frac23-\mathrm{i} \right\} \)
\( \left\{-\frac53;\frac13;\frac23+\mathrm{i} ;\frac23-\mathrm{i} \right\} \)
\( \left\{\frac53;-\frac13;-\frac23+\mathrm{i} ;-\frac23-\mathrm{i} \right\} \)
\( \left\{\frac53;-\frac13;\frac23+\mathrm{i} ;\frac23-\mathrm{i} \right\} \)

2010017903

Level: 
B
Suppose that the success rate of one specific medical treatment is \(80\,\%\). If the treatment is given to \(10\) new patients, what is the probability that it is effective in at least \(8\) of them? Round the result to four decimal places.
\(0.6778\)
\(0.1076\)
\(0.4094\)
\(0.1600\)

2010013307

Level: 
B
Find the values of the real coefficients \(a\), \(b\) and \(c\) such that the quadratic equation \[ ax^{2} + bx + c = 0 \] has solutions \(x_{1, 2} = \frac12\pm \mathrm{i}\).
\(a = 4,\ b = -4,\ c = 5\)
\(a = 4,\ b = 4,\ c = 5\)
\(a = 5,\ b = -5,\ c = 4\)
\(a = -4,\ b = 4,\ c = 5\)

2010013306

Level: 
B
Find the set of all values of the parameter \(p\in \mathbb{R}\) for which the following quadratic equation has solutions with nonzero imaginary part. \[ 9px^{2} + 5x + p = 0 \]
\(\left (-\infty ;-\frac{5} {6}\right )\cup \left (\frac{5} {6};\infty \right )\)
\(\left (-\frac{5} {6}; \frac{5} {6}\right )\)
\(\left (\frac{5} {6};\infty \right )\)
\(\left \{-\frac{5} {6}; \frac{5} {6}\right \}\)
\(\mathbb{R}\setminus \left \{-\frac{5} {6}; \frac{5} {6}\right \}\)