--- title: Endterm Sample Spring 2026 tags: - Sample - Endterm - DiscreteMathematics - Maths description: Discrete Mathematics - Endterm Sample - Spring 2026 --- # Endterm Sample Spring 2026 # Discrete Mathematics - Endterm Sample - Spring 2026 **NAME:** **NEPTUN code:** **Group number/Class Teacher:** > [!abstract] Exam details > > - **Duration:** 90 minutes. > - **Total score:** 40 points. > - **Success criterion:** At least 16 points. > - **Equipment:** Only blank paper and pen – no calculators. ## Instructions - Each task must be solved on paper using pen. - Write your name, Neptun code, and teacher’s name on the top of this test paper; also write your name and Neptun code on every page you use. - After finishing, place all solution papers behind this test paper and fold them in half (parallel to the longer side) so they stay together. - This test paper will be shared on Canvas. > [!warning] Justification required > > Justify your answers to **every question except Question 1** — brief justifications suffice. A *yes/no* answer without justification scores **0 marks** (except Q1). > [!tip] Leave it unevaluated > > You may leave binomial coefficients or factorials as-is — no calculator is needed. > [!info] > > In **Question 6** you have a choice between two versions. Solve only one of them. --- ## Questions ### 1. (7 marks) *Proofs are not required – only the answers.* 1. In a running race there are $24$ participants. How many different outcomes are possible for the first $5$ places? 2. In how many different ways can $5$ identical gifts be distributed among $12$ people, if each person can get at most one gift? 3. How many different strings can be formed using exactly the following letters: $A, A, A, B, C, C, D, D, D$? 4. In how many different ways can $12$ different gifts be distributed among $7$ people, if anyone can get any number of gifts? 5. In how many different ways can $20$ people sit down around a round table? (Rotations are considered identical.) 6. In how many different ways can $8$ identical apples be distributed among $11$ children? 7. At least how many people do we need to have in a group to be **certain** that there are $3$ among them who were born in the same month of the year? --- ### 2. (3 marks) The administration office at the Faculty of Informatics is planning to purchase **100 mouse pads** in total. There are four different types. 1. In how many different ways can they choose the $100$ mouse pads? (Types are distinguished, pads of the same type are identical.) 2. In how many ways if they order **at least $5$ mouse pads of each type**? --- ### 3. (7 marks) Boris has $10$ books and puts them all on one shelf in a row. Three of them are: *War and Peace* (W), *Pride and Prejudice* (P), *Crime and Punishment* (C). 1. In how many ways can he arrange the $10$ books so that **W and P are not next to each other**? 2. In how many ways so that **W, P, and C are next to each other** (in some order)? 3. In how many ways so that **W is the first book** and **C is not the last book**? --- ### 4. (9 marks) Consider 7-digit numbers formed exactly from the digits: $0, 1, 2, 3, 4, 4, 5$. 1. How many such 7-digit numbers exist? 2. How many of them are divisible by $5$? 3. How many have the **last digit not equal to $4$**? --- ### 5. (7 marks) 1. In the expansion of $$ \left(4x^{5} - \frac{2}{x^{3}}\right)^{10} $$ find the coefficients of the terms $x^{50}$ and $x^{27}$. 2. A school has $150$ students. Activities: chess (C), volleyball (V), badminton (B). Given: $|C| = 45,\ |V| = 54,\ |B| = 72,$ $|C \cap V| = 17,\ |C \cap B| = 26,\ |V \cap B| = 21,$ $37$ students do none of these. How many take part in **all three** activities? --- ## Question 6 (choose only one version) ### Version 1 (7 marks) After the exam, $20$ DM1 students attend a dance. 1. In how many ways can they form **one circle** so that Anna and Bella stand next to each other, but Anna does **not** stand next to Celia? 2. Exactly $10$ men and $10$ women. In how many ways can they form **one circle** so that men and women alternate (no two men or two women are adjacent)? --- ### Version 2 (7 marks) For each sequence below, decide if there exists (1) a **graph** (2) a **simple graph** with the given degree sequence. If yes, draw an example; if not, prove impossibility. 1. $5,4,3,3,3,2,2$ 2. $6,4,4,4,4,2,0$ 3. $6,5,4,4,3,2,1$ ---