BD math Olympiad 2024 regional questions
āĻŦāĻā§ā§āĻž āĻāĻā§āĻāϞāĻŋāĻ āĻāĻŖāĻŋāϤ āĻ
āϞāĻŋāĻŽā§āĻĒāĻŋā§āĻžāĻĄ
āĻā§āϝāĻžāĻāĻžāĻāϰāĻŋ: āĻĒā§āϰāĻžāĻāĻŽāĻžāϰāĻŋ (ā§Šā§ -ā§ĢāĻŽ āĻļā§āϰā§āĻŖāĻŋ)
1. 5 āĻĨā§āĻā§ 15 āĻĒāϰā§āϝāύā§āϤ āϏāĻāϞ āĻā§āĻĄāĻŧ āϏāĻāĻā§āϝāĻžāϰ āϝā§āĻāĻĢāϞ āύāĻŋāϰā§āĻŖāϝāĻŧ āĻāϰā§āĨ¤
Find the sum of all even numbers from 5 to 15.
2. 350 āĻāϰ āϏāĻžāĻĨā§ āύā§āϝā§āύāϤāĻŽ āĻā§āύ āϧāύāĻžāϤā§āĻŽāĻ āĻĒā§āϰā§āĻŖāϏāĻāĻā§āϝāĻž āϝā§āĻ āĻāϰāϞ⧠āϏāĻāĻā§āϝāĻžāĻāĻŋ āĻāĻāĻāĻŋ āĻĒā§āϰā§āĻŖāϏāĻāĻā§āϝāĻž āĻšāĻŦā§?(āĻā§āύ⧠āĻĒā§āϰā§āĻŖāϏāĻāĻā§āϝāĻž āĻāĻŽāύ āĻāĻāĻāĻŋ āĻŦāϰā§āĻāϏāĻāĻā§āϝāĻž āĻĨāĻžāĻā§ āϝā§āĻā§āύ⧠āĻĒā§āϰā§āĻŖāϏāĻāĻā§āϝāĻž āĻāĻŦāĻ āĻ āĻāĻāĻāĻŋ āĻĒā§āϰā§āĻŖāϏāĻāĻā§āϝāĻžāϰ āĻā§āĻŖāĻĢāϞā§āϰ āĻāĻāĻžāϰ⧠āĻĒā§āϰāĻāĻžāĻļ āĻāϰāĻž āϝāĻžāϝāĻŧāĨ¤ āϝā§āĻŽāύāĻ 25 = 5 à 5, 36 = 6 à 6 āĻāϤā§āϝāĻžāĻĻāĻŋ )
What is the smallest integer that is to be added with đđđ so that it becomes a perfect square number? (A perfect square is a number that can be expressed as the product of an integer by itself. Such as: đđ = đ Ã đ, đđ = đ Ã đ etc)
3. āĻā§āϝā§āϤāĻŋ āĻāĻāĻāĻŋ āϰā§āϏā§āĻā§āϰā§āύā§āĻā§ āĻāĻŋā§ā§āĻā§, āϝā§āĻāĻžāύ⧠āĻā§āĻžāĻāĻĢāĻžāĻ āϏā§āĻŦāĻŋāϧāĻž āĻāĻā§āĨ¤ āϏ⧠āĻā§ā§āĻāĻžāϰāĻā§ āĻā§āĻžāĻāĻĢāĻžāĻā§ā§āϰ āĻĒāĻžāϏāĻā§āĻžāϰā§āĻĄā§āϰ āĻŦā§āϝāĻžāĻĒāĻžāϰ⧠āĻāĻŋāĻā§āĻā§āϏ āĻāϰāĻžā§, āϤāĻŋāύāĻŋ āύāĻŋāĻā§āϰ āĻāĻŋāϤā§āϰāĻā§āĻāĻŋāĻāĻŋ āĻĻāĻŋāϞā§āύ āĻāĻŦāĻ āĻŦāϞāϞā§āύ āϝ⧠āĻĒāĻžāϏāĻā§āĻžāϰā§āĻĄāĻāĻŋ āĻāĻāĻāĻŋ āϏāĻāĻā§āϝāĻžāĨ¤ *(āϏā§āĻāĻžāϰ) āĻāĻŋāĻšā§āύāĻŋāϤ āϏāĻāĻā§āϝāĻžāĻāĻŋ āĻĒāĻžāϏāĻā§āĻžāϰā§āĻĄ āĻšāϞ⧠āĻāĻŦāĻ āĻĒā§āϰāϤāĻŋāĻāĻŋ āĻāĻāϰā§āĻāĻŋ āĻŦāϰā§āĻŖ āĻāĻāĻāĻŋ āĻāϰ⧠āĻ āĻā§āώāϰ āύāĻŋāϰā§āĻĻā§āĻļ āĻāϰāϞā§, āĻĒāĻžāϏāĻā§āĻžāϰā§āĻĄā§āϰ āϏāĻāĻā§āϝāĻžāĻāĻŋ āύāĻŋāϰā§āϧāĻžāϰāĻŖ āĻāϰā§āĨ¤

Juty went to a restaurant, where WiFi service is available. When she asked the waiter about the WiFi password, the waiter gave her the following piece of paper and told her that the password is a number. If the *(star) marked number is the password and each letter represents a digit, then find the number of the password.
4. 100 āĻāϰ āĻā§ā§ā§ āĻā§āĻ āĻāĻŽāύ āĻāϤāĻāĻŋ āĻŽā§āϞāĻŋāĻ āϏāĻāĻā§āϝāĻžāĻā§ā§ āĻĒāĻžāĻā§āĻž āϝāĻžāĻŦā§, āϝāĻžāĻĻā§āϰ āĻŦāĻŋāϝā§āĻāĻĢāϞ āĻāĻāĻāĻŋ āĻŽā§āϞāĻŋāĻ āϏāĻāĻā§āϝāĻž āĻšāĻŦā§?
How many prime-pair smaller than 100 are there, such that their difference is a prime number?
5. āĻĒā§āϰāϤāĻŋāĻāĻŋ āϞāĻžāĻāύ āĻŦāϰāĻžāĻŦāϰ āĻāĻžāϰāĻāĻŋ āĻāĻŋāύā§āύ āĻŦāĻŋāύā§āĻĻā§āϰ āϏāĻāĻā§āϝāĻžāĻā§āϞā§āϰ āϝā§āĻāĻĢāϞ 2024āĨ¤
āϝāĻĻāĻŋ a < b < c < d, b = \[\frac{a+c}{2}\] āĻāĻŦāĻ d = c+5 āĻšā§,
āϤāĻžāĻšāϞ⧠d āĻāϰ āĻŽāĻžāύ āύāĻŋāϰā§āĻŖā§ āĻāϰā§āĨ¤
The sum of the four dots on each line is đđđđ. If đ <đ < đ < đ , đ = \[\frac{a+c}{2}\] and đ = đ + đ, then find the value of đ .
6. āĻāĻŋāϤā§āϰā§, DC = 8, CB = 4, BA = 8 āĻšāϞā§, āĻāĻžā§āĻžāĻā§āϤ āĻ āĻāĻļāĻāĻŋāϰ āĻā§āώā§āϤā§āϰāĻĢāϞ āύāĻŋāϰā§āĻŖā§ āĻāϰā§āĨ¤

In the figure, if đĢđĒ = đ, đĒđŠ = đ, đŠđ¨ = đ, then find the area of the shadow marked region.
7. āĻāĻāĻāĻŋ āϧāĻžāϰāĻžāϰ n-āϤāĻŽ āĻĒāĻĻ āĻšāϤ⧠n-1-āϤāĻŽ āĻĒāĻĻā§āϰ āĻŦāĻŋāϝā§āĻāĻĢāϞāĻā§ āĻĒāĻĻ āĻĻā§āĻāĻāĻŋāϰ āĻā§āĻŖāĻĢāϞ āĻĨā§āĻā§ āĻŦāĻŋāϝā§āĻ āĻāϰāϞ⧠n+1-āϤāĻŽ āĻĒāĻĻ āĻĒāĻžāĻā§āĻž āϝāĻžā§āĨ¤ āϧāĻžāϰāĻžāĻāĻŋāϰ āĻĒā§āϰāĻĨāĻŽ āĻĻā§āĻāĻāĻŋ āĻĒāĻĻ 1 āĻ 2 āĻšāϞā§, 999-āϤāĻŽ āĻĒāĻĻ āύāĻŋāϰā§āĻŖā§ āĻāϰā§āĨ¤
By subtracting the (đ â đ)th term of a series from the đth term and then subtracting the result from the product of those two terms, you can find the (đ + đ)th term of the series. If the first two terms are đ and đ, then find the đđđth term.
8. OA = 4 āĻāĻŦāĻ OBDF āĻŦāϰā§āĻ OD = 10āĨ¤ āĻāĻžāϞ⧠āĻ āĻāĻļāĻāĻŋāϰ āĻā§āώā§āϤā§āϰāĻĢāϞāĻā§ \[\frac{a}{2} – b\pi\] āĻāĻāĻžāϰ⧠āϞā§āĻāĻž āϝāĻžā§āĨ¤ a + b-āĻāϰ āĻŽāĻžāύ āύāĻŋāϰā§āĻŖā§ āĻāϰā§āĨ¤

đļđ¨ = đ and in the square đļđŠđĢđ, đļđĢ = đđ. The area of the shadowed region can be written as \[\frac{a}{2} – b\pi\]. Find the value of đ + đ.
āĻŦāĻā§ā§āĻž āĻāĻā§āĻāϞāĻŋāĻ āĻāĻŖāĻŋāϤ āĻ
āϞāĻŋāĻŽā§āĻĒāĻŋā§āĻžāĻĄ
āĻā§āϝāĻžāĻāĻžāĻāϰāĻŋ: āĻā§āύāĻŋā§āϰ (ā§Ŧāώā§āĻ -ā§ŽāĻŽ āĻļā§āϰā§āĻŖāĻŋ)
1. āĻŽāĻžāĻā§āĻĻā§āϰ āĻšāĻžāϤ⧠āĻĻā§āĻāĻŋ āĻāĻžāĻĻā§āϰ āĻĒāĻžāĻĨāϰ āĻāĻā§āĨ¤ āϤāĻžāĻĻā§āϰāĻā§ āĻāĻāĻŦāĻžāϰ āĻāώāĻž āĻĻāĻŋāϞ⧠āĻĒā§āϰāϤā§āϝā§āĻāĻāĻŋ āĻĒāĻžāĻĨāϰ āĻĨā§āĻā§ āĻāĻāĻāĻŋ āĻāϰ⧠āĻĒāĻžāĻĨāϰ āĻŦā§āϰ āĻšā§āĨ¤ āĻĒāĻžāĻĨāϰ āϏāĻāĻā§āϝāĻž 100 āĻšāĻā§āĻžāϰ āĻāύā§āϝ āĻāϤāĻŦāĻžāϰ āĻĒāĻžāĻĨāϰ āĻāώāϤ⧠āĻšā§ā§āĻāĻŋāϞ?
Majed has two magic stones in his hand. If they are rubbed once, a stone will come out from each stone. How many times the stones had to be rubbed to make the stone
number đđđ?
2. āĻļā§āϧā§āĻŽāĻžāϤā§āϰ 16 āϏāĻāĻā§āϝāĻž āĻŦā§āϝāĻŦāĻšāĻžāϰ āĻāϰ⧠61 āĻŦāĻžāύāĻžāϤ⧠āĻšāĻŦā§āĨ¤ āϏāĻšāĻžā§āĻ āĻšāĻŋāϏāĻžāĻŦā§ āϝā§āĻ, āĻŦāĻŋāϝāĻŧā§āĻ, āĻā§āĻŖ, āĻāĻžāĻ āĻāĻŦāĻ āĻŦāϰā§āĻāĻŽā§āϞ āĻŦā§āϝāĻŦāĻšāĻžāϰ āĻāϰāĻž āϝāĻžāĻŦā§āĨ¤ āĻāĻāĻž āĻāϰāϤ⧠āϏāϰā§āĻŦāύāĻŋāĻŽā§āύ āĻāϤāĻāĻŋ 16 āĻĒā§āϰā§ā§āĻāύ āĻšāĻŦā§? (āϧāĻžāϰāĻŖāĻā§āώāĻŽ āϏāĻāĻā§āϝāĻž āĻāϞā§āϞā§āĻ āĻāϰā§āĨ¤)
đđ has to be made by only using the number đđ. Addition, subtraction, multiplication,division and square root can be used as helpers. Minimum how many đđ will be needed for this? (Avoid negative numbers)
3. \[2^{20} \times 3^{10} \times 5^8\] āϏāĻāĻā§āϝāĻžāĻāĻŋāϰ āĻāϤāĻā§āϞ⧠āĻĒā§āϰā§āĻŖ āĻāύ āĻā§āĻĒāĻžāĻĻāĻ āĻāĻā§?
How many cubic factors does the number \[\(2^{20} \times 3^{10} \times 5^8\] have?
4. OA = 2 āĻāĻŦāĻ OBDF āĻŦāϰā§āĻ OD = 8 āĨ¤ āĻāĻžāϞ⧠āĻ āĻāĻļāĻāĻŋāϰ āĻā§āώā§āϤā§āϰāĻĢāϞāĻā§ \[\frac{a – \pi}{b}\] āĻāĻāĻžāϰ⧠āϞā§āĻāĻž āϝāĻžā§āĨ¤ a + b-āĻāϰ āĻŽāĻžāύ āύāĻŋāϰā§āĻŖāϝāĻŧ āĻāϰā§āĨ¤

đļđ¨ = đ and in the square đļđŠđĢđ, đļđĢ = đ. The area of the shadowed region can be written as đ â đ đ. Find the value of đ + đ.
5. āĻāύāύ āĻāĻāĻāĻŋ āĻāĻžāĻā§āϰ āĻā§āϞāĻā§āϰ āĻāĻŋāϤāϰ āĻŦāύā§āĻĻāĻŋāĨ¤ āϏ⧠āĻā§āϞāĻā§āϰ āĻĒā§āώā§āĻ ā§āϰ āϏāĻžāĻĨā§ āĻĻāĻžāĻĄāĻŧāĻŋāϝāĻŧā§ āĻāĻāĻāĻŋ āϞā§āĻāĻžāϰ āϞāĻžāĻāĻ āĻāĻŽāύāĻāĻžāĻŦā§ āϧāϰ⧠āϝ⧠āϤāĻž āĻā§āϞāĻā§āϰ āĻāĻŋāϤāϰā§āϰ āĻĒā§āώā§āĻ ā§ āĻāĻāĻāĻŋ āύāĻŋāϰā§āĻĻāĻŋāώā§āĻ āĻā§āĻŖā§ āĻŦāĻžāĻāĻ āĻšāϝāĻŧāĨ¤ āϝāĻĻāĻŋ \[\alpha = 60^\circ\] āĻšāϝāĻŧ, āϤāĻžāĻšāϞ⧠āϞāĻžāĻāĻāĻāĻŋ āĻā§āϞāĻā§āϰ āĻĒā§āώā§āĻ ā§ 2 āĻŦāĻžāϰ āĻŦāĻžāĻāĻ āύāĻŋāϝāĻŧā§ āĻāύāĻžāύā§āϰ āĻāĻžāĻā§ āĻĢāĻŋāϰ⧠āĻāϏā§āĨ¤ \[\alpha = 20^\circ\] āĻšāϞā§, āϞāĻžāĻāĻāĻāĻŋ āϏāϰā§āĻŦāύāĻŋāĻŽā§āύ āĻāϤāĻŦāĻžāϰ āĻŦāĻžāĻāĻ āύāĻŋāϝāĻŧā§ āĻāύāĻžāύā§āϰ āĻāĻžāĻā§ āĻĢāĻŋāϰ⧠āĻāϏāĻŦā§?
Emon is trapped inside a glass sphere. He stood against the surface of the sphere and held a laser beam so that it makes a particular angle with the inner surface of the sphere.If đļ = đđ°, then the light reflects đ times on the surface of the sphere and returns to Emon. If đļ = đđ°, then minimum how many number of turns will the light take to return to Emon?
6. āĻāĻŋāϤā§āϰā§āϰ āϤāĻŋāύāĻāĻŋ āϏāĻŽāĻžāύ āĻŦā§āϤā§āϤ āĻāĻā§ āĻ āĻĒāϰāĻā§ āĻŦāĻšāĻŋāĻāϏā§āĻĒāϰā§āĻļ āĻāϰā§āĨ¤ āĻŦā§āϤā§āϤāĻā§āϞā§āϰ āĻŦā§āϝāĻžāϏāĻžāϰā§āϧ 8āĨ¤ āĻāĻžāĻĸāĻŧāĻā§āϤ āĻ āĻāĻļā§āϰ āĻā§āώā§āϤā§āϰāĻĢāϞāĻā§ \[a\sqrt{b} – c \pi\] āĻāĻāĻžāϰ⧠āĻĒā§āϰāĻāĻžāĻļ āĻāϰāĻž āϝāĻžāϝāĻŧāĨ¤ a + b + c-āĻāϰ āĻŽāĻžāύ āύāĻŋāϰā§āĻŖāϝāĻŧ āĻāϰā§āĨ¤

The three circles in the figure externally touches each other. The radius of the circles are đ. The area of the shaded region can be represented by \[a\sqrt{b} – c \pi\]. Find the value of đ + đ + đ.
7. āĻāĻāĻāĻŋ āĻāĻžāĻ ā§āϰ āĻāĻŋāĻāĻŦ, āϝāĻžāϰ āĻāĻ āĻŦāĻžāĻšā§ n āĻāĻāĻ, āϤāĻžāϰ āϏāĻŽāϏā§āϤ āϤāϞ⧠āϞāĻžāϞ āϰāĻ āĻāϰāĻž āĻšāϞ⧠āĻāĻŦāĻ \[n^3 \] āĻāĻŋ āĻāĻāĻ āĻāĻŋāĻāĻŦ āĻāϰ⧠āĻāĻžāĻāĻž āĻšāϞā§āĨ¤ āĻāĻāĻ āĻāĻŋāĻāĻŦāĻā§āϞā§āϰ āϤāϞā§āϰ āĻŽā§āĻ āĻā§āώā§āϤā§āϰāĻĢāϞ āĻ āĻŋāĻ āĻāĻ-āĻ āώā§āĻāĻŽāĻžāĻāĻļ āϞāĻžāϞāĨ¤ āĻāĻāĻ āĻāĻŋāĻāĻŦāĻā§āϞā§āϰ āĻāϤ āĻĒāĻžāĻļā§ āύāϤā§āύ āĻāϰ⧠āϞāĻžāϞ āϰāĻ āĻāϰāϤ⧠āĻšāĻŦā§, āϝā§āύ āϏā§āĻā§āϞā§āϰ āĻŽā§āĻ āĻĒāĻžāĻļā§āϰ āĻāĻ-āĻāϤā§āϰā§āĻĨāĻžāĻāĻļ āϞāĻžāϞ āĻšāϝāĻŧ?
A wooden cube, đ unit on a side, is painted red on all faces and then cut into đđ unit cubes. Exactly one-eighth portions of the total number of faces of unit cubes are red. How many sides of the smaller cubes need to be newly painted red, so that exactly onefourth portion of the total number of faces of the unit cubes are red?
8. āύāĻŋāϞāϝ āĻāĻŋāϤā§āϰā§āϰ āĻŽāϤ⧠āĻĒā§āϝāĻžāĻāĻžāϰā§āύ āĻāĻāĻāϞ⧠M āĻŦāĻŋāύā§āĻĻā§ āĻāĻŦāĻ N āĻŦāĻŋāύā§āĻĻā§āϰ āĻŽāĻžāĻā§ āĻĒāĻžāĻļāĻžāĻĒāĻžāĻļāĻŋ āĻĻā§āϰāϤā§āĻŦ a āĻāĻŦāĻ āĻāĻĒāϰā§āϰ āύāĻŋāĻā§ āĻĻā§āϰāϤā§āĻŦ b āĻĒāĻžāĻā§āĻž āϝāĻžā§āĨ¤ āĻāĻ āĻĒā§āϝāĻžāĻāĻžāϰā§āύ 1
āĻĨā§āĻā§ 2024 āĻĒāϰā§āϝāύā§āϤ āĻāĻāĻāĻž āĻšāϞ⧠āĻāĻŦāĻ a, b āĻāϰ āĻŽāĻžāύ āĻŦā§āϰ āĻāϰāĻž āĻšāϞā§āĨ¤ āĻĒāϰāĻŦāϰā§āϤ⧠āĻā§āώā§āϤā§āϰ⧠\[\frac{b}{a}\] āĻāϰ āĻŽāĻžāύ āύāĻŋāϰā§āĻŖā§ āĻāϰā§āĨ¤

Niloy drew a pattern similar to that shown in the figure, the horizontal distance between the points đ´ and đĩ is âđâ and the vertical distance between the points đ´ and đĩ is âđâ.This pattern is drawn from đ to đđđđ and the value of đ, đ is extracted. Find the value of \[\frac{b}{a}\] in the latter case.

