2010020106
Level:
A
Find the probability that a randomly selected two-digit number is even.
\(45/90\)
\(51/90\)
\(49/90\)
\(50/90\)
Probability
2010020105
Level:
A
Find the probability that a randomly selected two-digit number is odd.
\(45/90\)
\(51/90\)
\(49/90\)
\(50/90\)
2010020104
Level:
A
Two dice are thrown at the same time. Which of the following statements is true?
The probability that we get the sum \(4\) is the same as the probability that we obtain the sum \(10\).
The probability that we get the sum \(10\) is the highest possible.
The probability that we get the sum \(10\) is three times greater than the probability that we obtain the sum \(4\).
None of the above is true.
2010020103
Level:
A
Two dice are thrown at the same time. Which of the following statements is true?
The probability that we get the sum \(9\) is the same as the probability that we obtain the sum \(5\).
The probability that we get the sum \(9\) is two times greater than the probability that we obtain the sum \(5\).
The probability that we get the sum \(9\) is the highest possible.
None of the above is true.
2010020102
Level:
A
An urn contains \(19\) red balls and \(9\) blue balls. Find the minimum number of blue balls that must be added so that the probability of drawing a blue ball is greater than \(0.65\).
\(27\)
\(17\)
\(7\)
\(47\)
2010020101
Level:
A
An urn contains \(12\) red balls and \(30\) blue balls. Find the minimum number of red balls that must be added so that the probability of drawing a red ball is greater than \(0.66\).
\(47\)
\(27\)
\(37\)
\(17\)
2010013606
Level:
A
In a set of \( 200 \) items, \( 20 \) are defective. We pick randomly \( 10 \) items from this set. First nine items were not defective. Find the probability that the tenth item selected is not defective too. Results are rounded to three decimal places.
\( \frac{171}{191}\doteq 0.895 \)
\( \frac{180}{191}\doteq 0.942 \)
\( \frac{180}{200}\doteq 0.9\)
\( \frac{1}{171}\doteq 0.006 \)
2010013605
Level:
A
The wooden cube with the edges of length \( 4\,\mathrm{cm} \) has faces painted in blue. Suppose we cut the cube into small unit cubes (the edge length is \( 1\,\mathrm{cm}\)) and select one of the unit cubes at random. What is the probability that the selected cube has at most one face painted in blue?
\( 0.5 \)
\( 0.375 \)
\( 0.438 \)
\( 0.75 \)
2010013604
Level:
A
Three dice are thrown. What is the probability that the sum is \(16\)?
\( \frac{6}{6^3}\doteq 0.028 \)
\( \frac{2}{6^3}\doteq 0.009 \)
\( \frac{12}{6^3}\doteq 0.056 \)
\( \frac{3}{6^3}\doteq 0.013 \)
2010013603
Level:
A
There are \( 28 \) students in the class, one of them is Boris. The teacher picks randomly four students to be tested. What is the probability that Boris is among them?
\( \frac{\binom{27}3}{\binom{28}4}\doteq 0.143 \)
\( \frac{\binom{27}4}{\binom{28}4}\doteq 0.857 \)
\( \frac{\binom{27}3}{\binom{28}3}\doteq 0.893 \)
\( \frac{\binom{27}{3}\binom{4}1}{\binom{28}{4}}\doteq 0.571 \)