isi-entrance

2024 UGA

26 maths questions

If $x = 1 + \sqrt[5]{2} + \sqrt[5]{4} + \sqrt[5]{8} + \sqrt[5]{16}$, then the value of $\left(1 + \frac{1}{x}\right)^{30}$ is
(A) 2
(B) 5
(C) 32
(D) 64
Let $j$ be a number selected at random from $\{1, 2, \ldots, 2024\}$. What is the probability that $j$ is divisible by 9 and 15?
(A) $\frac{1}{23}$
(B) $\frac{1}{46}$
(C) $\frac{1}{44}$
(D) $\frac{1}{253}$
Q3 Sequences and series, recurrence and convergence Linear Arrangement with Constraints View
Let $S_n$ be the set of all $n$-digit numbers whose digits are all 1 or 2 and there are no consecutive 2's. (Example: 112 is in $S_3$ but 221 is not in $S_3$). Then the number of elements in $S_{10}$ is
(A) 512
(B) 256
(C) 144
(D) 89
Q4 Binomial Distribution Compute Exact Binomial Probability View
There are 30 True or False questions in an examination. A student knows the answer to 20 questions and guesses the answers to the remaining 10 questions at random. What is the probability that the student gets exactly 24 answers correct?
(A) $\frac{105}{2^9}$
(B) $\frac{105}{2^8}$
(C) $\frac{105}{2^{10}}$
(D) $\frac{4}{2^{10}}$
Let $x_1, x_2, \ldots, x_n$ be non-negative real numbers such that $\sum_{i=1}^{n} x_i = 1$. What is the maximum possible value of $\sum_{i=1}^{n} \sqrt{x_i}$?
(A) 1
(B) $\sqrt{n}$
(C) $n^{3/4}$
(D) $n$
The precise interval on which the function $f(x) = \log_{1/2}\left(x^2 - 2x - 3\right)$ is monotonically decreasing, is
(A) $(-\infty, -1)$
(B) $(-\infty, 1)$
(C) $(1, \infty)$
(D) $(3, \infty)$
The angle subtended at the origin by the common chord of the circles $x^2 + y^2 - 6x - 6y = 0$ and $x^2 + y^2 = 36$ is
(A) $\pi/2$
(B) $\pi/4$
(C) $\pi/3$
(D) $2\pi/3$
Q9 Sine and Cosine Rules Multi-step composite figure problem View
In $\triangle ABC$, $CD$ is the median and $BE$ is the altitude. Given that $\overline{CD} = \overline{BE}$, what is the value of $\angle ACD$?
(A) $\pi/3$
(B) $\pi/4$
(C) $\pi/5$
(D) $\pi/6$
If the points $z_1$ and $z_2$ are on the circles $|z| = 2$ and $|z| = 3$, respectively, and the angle included between these vectors is $60^\circ$, then the value of $\frac{|z_1 + z_2|}{|z_1 - z_2|}$ is
(A) $\sqrt{\frac{19}{7}}$
(B) $\sqrt{19}$
(C) $\sqrt{7}$
(D) $\sqrt{\frac{7}{19}}$
Let $n \geqslant 1$. The maximum possible number of primes in the set $\{n+6, n+7, \ldots, n+34, n+35\}$ is
(A) 7
(B) 8
(C) 12
(D) 13
Q12 Combinations & Selection Distribution of Objects to Positions or Containers View
Suppose 40 distinguishable balls are to be distributed into 4 different boxes such that each box gets exactly 10 balls. Out of these 40 balls, 10 are defective and 30 are non-defective. In how many ways can the balls be distributed such that all the defective balls go to the first two boxes?
(A) $\frac{40!}{(10!)^4}$
(B) $\frac{30! \cdot 20!}{(10!)^5}$
(C) $\frac{20! \cdot 20!}{(10!)^5}$
(D) $\frac{30! \cdot 10!}{(10!)^4}$
Q13 Sign Change & Interval Methods Integer Solutions of an Inequality View
The number of elements in the set $$\left\{x : 0 \leqslant x \leqslant 2,\, \left|x - x^5\right| = \left|x^5 - x^6\right|\right\}$$ is
(A) 2
(B) 3
(C) 4
(D) 5
In a room with $n \geqslant 2$ people, each pair shakes hands between themselves with probability $\frac{2}{n^2}$ and independently of other pairs. If $p_n$ is the probability that the total number of handshakes is at most 1, then $\lim_{n \rightarrow \infty} p_n$ is equal to
(A) 0
(B) 1
(C) $e^{-1}$
(D) $2e^{-1}$
Q15 Sign Change & Interval Methods Number of Solutions / Roots via Curve Analysis View
The number of positive solutions to the equation $$e^x \sin x = \log x + e^{\sqrt{x}} + 2$$ is
(A) 0
(B) 1
(C) 2
(D) $\infty$
Q16 Number Theory GCD, LCM, and Coprimality View
Let $n > 1$ be the smallest composite integer that is coprime to $\frac{10000!}{9900!}$. Then
(A) $n \leqslant 100$
(B) $100 < n \leqslant 9900$
(C) $9900 < n \leqslant 10000$
(D) $n > 10000$
Let $P = \{(x, y) : x + 1 \geqslant y,\, x \geqslant -1,\, y \geqslant 2x\}$. Then the minimum value of $(x + y)$ where $(x, y)$ varies over the set $P$ is
(A) $-1$
(B) $-3$
(C) $3$
(D) $0$
Let $A = \{1, \ldots, 5\}$ and $B = \{1, \ldots, 10\}$. Then the number of ordered pairs $(f, g)$ of functions $f : A \rightarrow B$ and $g : B \rightarrow A$ satisfying $(g \circ f)(a) = a$ for all $a \in A$ is
(A) $\frac{10!}{5!} \times 5^5$
(B) $5^{10} \times 5!$
(C) $10! \times 5!$
(D) $\binom{10}{5} \times 10^5$
Q19 Arithmetic Sequences and Series Estimation or Bounding of a Sum View
Let $$S = \frac{1}{\sqrt{10000}} + \frac{1}{\sqrt{10001}} + \cdots + \frac{1}{\sqrt{160000}}$$ Then the largest positive integer not exceeding $S$ is
(A) 200
(B) 400
(C) 600
(D) 800
Q20 Inequalities Absolute Value Inequality View
The real number $x$ satisfies $$\frac{|x|^2 - |x| - 2}{2|x| - |x|^2 - 2} > 2$$ if and only if $x$ belongs to
(A) $(-2, -1) \cup (1, 2)$
(B) $(-2/3, 0) \cup (0, 2/3)$
(C) $(-1, -2/3) \cup (2/3, 1)$
(D) $(-1, 0) \cup (0, 1)$
Consider points of the form $\left(n, n^k\right)$, where $n$ and $k$ are integers with $n \geq 0$, $k \geq 1$. How many such points are strictly inside the circle of radius 10 with centre at the origin?
(A) 11
(B) 12
(C) 15
(D) 17
Q22 Binomial Theorem (positive integer n) Determine Parameters from Conditions on Coefficients or Terms View
Let $n > 1$, and let us arrange the expansion of $\left(x^{1/2} + \frac{1}{2x^{1/4}}\right)^n$ in decreasing powers of $x$. Suppose the first three coefficients are in arithmetic progression. Then, the number of terms where $x$ appears with an integer power, is
(A) 3
(B) 2
(C) 1
(D) 0
Q23 Arithmetic Sequences and Series Limit Evaluation Involving Sequences View
The limit $$\lim_{n \rightarrow \infty} \frac{2\log 2 + 3\log 3 + \cdots + n\log n}{n^2 \log n}$$ is equal to
(A) 0
(B) $1/4$
(C) $1/2$
(D) 1
Let $p < q$ be prime numbers such that $p^2 + q^2 + 7pq$ is a perfect square. Then, the largest possible value of $q$ is:
(A) 7
(B) 11
(C) 23
(D) 29
Q25 Indices and Surds Exponential Equation Solving View
The set of all real numbers $x$ for which $3^{2^{1-x^2}}$ is an integer has
(A) 3 elements
(B) 15 elements
(C) 24 elements
(D) infinitely many elements
Q26 Complex Numbers Argand & Loci Locus Identification from Modulus/Argument Equation View
Let $a, b, c$ be three complex numbers. The equation $$az + b\bar{z} + c = 0$$ represents a straight line on the complex plane if and only if
(A) $a = b$
(B) $\bar{a}c = b\bar{c}$
(C) $|a| = |b| \neq 0$
(D) $|a| = |b| \neq 0$ and $\bar{a}c = b\bar{c}$
In the adjoining figure, $C$ is the centre of the circle drawn, $A, F, E$ lie on the circle and $BCDF$ is a rectangle. If $\frac{DE}{AB} = 2$, then $\frac{FE}{FA}$ equals
(A) $\sqrt{\frac{3}{2}}$
(B) $\sqrt{2}$
(C) $\sqrt{\frac{5}{2}}$
(D) $\sqrt{3}$