Quiz: SQL Queries, Dosimetry and Rational Numbers — 13 questions

1. Which SQL condition identifies users who are missing from the most recent report?

A. Select users whose UserID is not in the report with the maximum ReportDate

B. Select users whose UserID is in the report with the minimum ReportDate

C. Select users whose UserID is in a report from the current year

D. Select users whose UserID matches every report date

Answer: (A)

Explanation

The latest report is identified by its maximum ReportDate, and users missing from it have UserIDs not contained in that report. A report with the minimum date represents the oldest report rather than the most recent one.

2. Which SQL query condition finds users who are currently active?

A. WHERE UserStatus = 'Inactive'

B. WHERE UserStatus = 'Active'

C. WHERE JoinDate = CURDATE()

D. WHERE DepartmentID IS NULL

Answer: (B)

Explanation

Filtering UserStatus for the value 'Active' returns users who are currently active. A current join date concerns when users joined, while a null department identifies missing department assignments.

3. Which SQL filter finds users whose role is Administrator, Manager, or Analyst?

A. WHERE UserStatus IN ('Administrator', 'Manager', 'Analyst')

B. WHERE UserName IN ('Administrator', 'Manager', 'Analyst')

C. WHERE UserRole IN ('Administrator', 'Manager', 'Analyst')

D. WHERE UserRole NOT IN ('Administrator', 'Manager', 'Analyst')

Answer: (C)

Explanation

The UserRole column must be checked against the three permitted role values with an IN condition. Filtering UserStatus or UserName tests the wrong attribute, while NOT IN excludes the intended users.

4. What is the mean dose of the whole lesion?

A. 5.556 Gy

B. 11.11 Gy

C. 55.6 Gy

D. 55.56 Gy

Answer: (C)

Explanation

The mean dose of the whole lesion is 55.6 Gy. The value 11.11 Gy is the dose delivered in one session, while 55.56 Gy is the calculated dose by fraction.

5. A session uses the stated calculation $5.556 \times 2$. What dose is delivered during that session?

A. 11.11 Gy

B. 55.6 Gy

C. 5.556 Gy

D. 55.56 Gy

Answer: (A)

Explanation

Multiplying $5.556$ by $2$ gives approximately $11.11$ Gy for one session. The whole-lesion mean dose and the plan-by-fraction dose describe different quantities.

6. Which prime decomposition correctly represents $60$?

A. $2^3 \cdot 3 \cdot 5$

B. $2 \cdot 3^2 \cdot 5$

C. $2^2 \cdot 3 \cdot 7$

D. $2^2 \cdot 3 \cdot 5$

Answer: (D)

Explanation

The prime factors of $60$ are $2,2,3,5$, giving $2^2 \cdot 3 \cdot 5$. The expression containing $7$ is the decomposition of $84$, while the other choices change a factor or exponent.

7. How is the GCD determined from the prime decompositions of two numbers?

A. Use noncommon prime factors with the smallest exponents

B. Use common prime factors with the largest exponents

C. Use every prime factor with the largest exponents

D. Use common prime factors with the smallest exponents

Answer: (D)

Explanation

The GCD retains only prime factors shared by both numbers and assigns each the smallest exponent present. Using all factors with the largest exponents describes the LCM instead.

8. What is the GCD of $60$ and $84$?

A. $6$

B. $12$

C. $24$

D. $420$

Answer: (B)

Explanation

The common prime factors are $2^2$ and $3$, so $\operatorname{GCD}(60,84)=2^2 \cdot 3=12$. The value $420$ is the corresponding least common multiple, not the greatest common divisor.

9. What is the value of $a^{-1}$ for a nonzero number $a$?

A. $a$

B. $1$

C. $a^{-2}$

D. $\frac{1}{a}$

Answer: (D)

Explanation

A power of negative one gives the reciprocal, so $a^{-1}=\frac{1}{a}$. The rule $a^1=a$ applies to exponent one, whereas $a^0=1$ applies to exponent zero.

10. What procedure reduces a fraction to irreducible form?

A. Subtract the denominator from the numerator repeatedly

B. Multiply both terms by their least common multiple

C. Divide both terms by their greatest common divisor

D. Divide the larger term by the smaller term

Answer: (C)

Explanation

A fraction reaches irreducible form when its numerator and denominator are divided by their greatest common divisor. Dividing the larger term by the smaller term does not generally preserve the fraction or produce its reduced form.

11. Which statement correctly describes the relationship between $\frac{20}{30}$ and $\frac{2}{3}$?

A. They represent different rational numbers because their terms differ

B. The first is irreducible, while the second can still be reduced

C. They are different representations of the same rational number

D. The second is obtained by adding the same number to both terms

Answer: (C)

Explanation

Dividing the numerator and denominator of $\frac{20}{30}$ by their greatest common divisor, 10, gives $\frac{2}{3}$, so both fractions have the same value. The first fraction is reducible, not irreducible, which rules out the related misconception.

12. Which calculation skill is included among the objectives for working with relative numbers?

A. Finding geometric areas from rational dimensions

B. Ordering numbers without carrying out calculations

C. Using addition, subtraction, multiplication, and division

D. Converting every rational number into a decimal

Answer: (C)

Explanation

The objectives include calculating with relative numbers through addition, subtraction, multiplication, and division. Converting all rational numbers to decimals is not identified as the stated calculation objective.

13. What kind of task is included in the objectives for rational numbers?

A. Solving problems involving rational numbers

B. Representing rational numbers on geometric figures

C. Memorizing decimal expansions of rational numbers

D. Classifying fractions by the size of their denominators

Answer: (A)

Explanation

Solving problems involving rational numbers is explicitly included among the objectives. Classifying fractions by denominator size may be useful in some contexts, but it does not express the stated problem-solving objective.