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SEAMO 2027 - Paper D - SET 04 - Self-study

Question 1

SEAMO self-study edition 2027; not an official 2027 paper. Original source years are retained. 25 questions, 90 minutes; Q1–10: 3 points, Q11–20: 4 points, Q21–25: 6 points, total 100. Original response types and all subparts are preserved. Verified is an editorial convention; source defects, necessary assumptions and unresolved mathematical uncertainty are disclosed.

It is known that $m,n,p$ are positive integers, where $m\lt n\lt p$. If $2^m+2^n+2^p=2336$, find $m$.
  1. 4
  2. 5
  3. 6
  4. 7
  5. Unable to determine

Question 2

Given that $a,b,c$ are positive real numbers and $a+b+c=1$, evaluate the following expression by choosing the correct option:
$$\sqrt{4a+1}+\sqrt{4b+1}+\sqrt{4c+1}.$$
  1. 4
  2. 5
  3. $<4$
  4. $>5$
  5. None of the above

Question 3

Let $k$ be a real number. Find the least value of $k$ such that the following inequality is correct:
$$\sqrt{x-2}+\sqrt{7-x}\le k.$$

Interpretation for this practice: the inequality must hold for every real $x$ for which both radicals are defined, namely $2\le x\le7$. The source leaves this quantifier implicit.
  1. $\sqrt5$
  2. $\sqrt{10}$
  3. $\sqrt2+\sqrt3$
  4. 3
  5. $2\sqrt3$

Question 4

Let $n$ be a positive integer such that $n^2+15n+36$ is a perfect square. Find $n$.
  1. 13
  2. 14
  3. 15
  4. 16
  5. None of the above

Question 5

If $7.03^3=347.428927$, then $0.703^3$ is equal to what?

Original printed options:

(A) 0.034728927

(B) 0.34728927

(C) 3.4728927

(D) 0.0034728927

(E) 0.00034728927

Source correction: none of the five printed options equals the exact result. All original options are retained for comparison; enter the exact numerical value instead of a letter.

Question 6

How many fractions in the list $\frac1{99},\frac2{99},\frac3{99},\ldots,\frac{98}{99}$ cannot be reduced to a simpler form?
  1. 45
  2. 60
  3. 75
  4. 90
  5. None of the above

Question 7

A bag contains 20 balls numbered 1 to 20. If 2 balls are randomly chosen from the bag, find the probability that the sum of the two numbers is prime.
  1. $\frac{23}{40}$
  2. $\frac{29}{40}$
  3. $\frac{31}{380}$
  4. $\frac{17}{190}$
  5. None of the above

Question 8

Evaluate
$$\frac12+\frac24+\frac38+\frac4{16}+\cdots+\frac8{2^8}.$$
  1. $\frac{249}{128}$
  2. $\frac{251}{128}$
  3. $\frac{449}{256}$
  4. $\frac{551}{256}$
  5. None of the above

Question 9

A football match can be won, drawn or lost with equal probability. A school plays 2 matches each week. The probability that at least one match is drawn that week is $m/n$. Find $m+n$.

Practice assumptions: the results of the two matches are independent, and m/n is written in lowest terms with positive integers m and n. These conditions are implicit, not expressly stated in the source.
  1. 13
  2. 14
  3. 15
  4. 16
  5. 17

Question 10

How many distinct integers are there among the following numbers?
$$\left\lfloor\frac{1^2+1}{100}\right\rfloor,\left\lfloor\frac{2^2+2}{100}\right\rfloor,\left\lfloor\frac{3^2+3}{100}\right\rfloor,\ldots,$$
$$\left\lfloor\frac{100^2+100}{100}\right\rfloor.$$
Here $\lfloor a\rfloor$ denotes the greatest integer less than or equal to $a$.

Question 11

Given that $m-2$ is a positive integer and is also a factor of $3m^2-2m+10$, find the sum of all such values of $m$.
  1. 15
  2. 26
  3. 51
  4. 62
  5. None of the above

Question 12

Let $a,b$ be positive real numbers such that
$$\frac1a+\frac1b=\frac5{a-b}.$$
Evaluate $\left(\frac ab+\frac ba\right)^2$.
  1. 29
  2. $16\sqrt5$
  3. $25\sqrt2$
  4. 36
  5. None of the above

Question 13

Suppose $ABCD$ is a square of side length 1. $M$ is the midpoint of $AB$. Find the area of the shaded region in the original figure.

Question illustration
  1. $\frac18$
  2. $\frac1{10}$
  3. $\frac1{12}$
  4. $\frac2{25}$
  5. None of the above

Question 14

Find the number of non-negative integer solutions $(a,b,c,d)$ to
$$a+b+c+d\le12.$$
  1. 1772
  2. 1800
  3. 1820
  4. 1825
  5. None of the above

Question 15

It is known that $p$ is a prime number. If $p^2+2$ is also prime, find $p$.
  1. 2
  2. 3
  3. 5
  4. 7
  5. None of the above

Question 16

Given that $x$ is an integer, find the number of integral values of
$$\frac{6x+3}{2x-1}.$$
  1. 4
  2. 5
  3. 6
  4. 7
  5. 8

Question 17

A circle is inscribed in a triangle of side lengths 3, 4 and 5. What is the radius of the circle?

Question illustration
  1. 1
  2. $\sqrt2$
  3. $\sqrt3$
  4. 2
  5. None of the above

Question 18

$ABCD$ is a square of side length 10 cm. $E$ and $F$ are the midpoints of $BC$ and $AB$, respectively. Find the area of $\triangle GDC$ in $\mathrm{cm}^2$, where $G$ is the intersection of $DE$ and $FC$ shown in the original figure.

Question illustration
  1. 12
  2. 14
  3. 16
  4. 20
  5. 22

Question 19

The integer $N$ is formed by writing all integers from 1001 to 1021 consecutively, that is, $N=100110021003\ldots1021$. Find the greatest power of 3 that is a factor of $N$.
  1. 9
  2. 27
  3. 81
  4. 243
  5. None of the above

Question 20

Mr. Woodley paid 650,000 dollars for two commercial properties. A year later, the market value of the first property rose by 20%, while that of the second dropped by 25%. The two properties then had the same market value. What was the market value of the first property at first?
  1. 220,000 dollars
  2. 230,000 dollars
  3. 240,000 dollars
  4. 250,000 dollars
  5. None of the above