LFM Stats And Pure

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turkey-yks 2020 Q18 Quadratic equation with parametric or self-referential conditions View
Where $a$ and $b$ are positive real numbers,
$$2ax^2 - 5bx + 8b = a$$
the roots of the equation are $a$ and $b$. Accordingly, what is the sum $a + b$?
A) 5
B) 6
C) 10
D) 12
E) 15
turkey-yks 2020 Q21 Geometric or real-world application leading to a quadratic equation View
In a neighborhood with 95 buildings, each building is either 2 or 3 stories. Within the scope of urban renewal, 15 of these buildings are demolished and replaced with 5-story buildings each, and the total number of stories of the buildings in the neighborhood increases from 240 to 274.
Accordingly, by what percentage did the number of 3-story buildings in the neighborhood decrease as a result of urban renewal?
A) 16
B) 18
C) 20
D) 22
E) 24
turkey-yks 2020 Q23 Geometric or real-world application leading to a quadratic equation View
Duygu, who starts running on a running course, takes a break to rest after running a certain distance.
After the break, Duygu
  • if she runs 240 meters more, she will have run $\frac{7}{12}$ of the entire course,
  • if she runs $\frac{1}{3}$ of the distance she ran before, she will have run $\frac{3}{5}$ of the entire course.

Accordingly, what is the length of the entire course in meters?
A) 1440
B) 1620
C) 1800
D) 1980
E) 2160
turkey-yks 2023 Q20 Geometric or real-world application leading to a quadratic equation View
Uncle Ahmet has a rectangular field with side lengths $x + 20$ and $2x + 30$ meters. He grows sunflowers in a square-shaped part with side length $x$ meters as shown in the figure.
If the area of the remaining part of the field is 1400 square meters, what is the perimeter of the entire field in meters?
A) 148 B) 154 C) 160 D) 166 E) 172
turkey-yks 2024 Q2 Finding a ratio or relationship between variables from an equation View
For positive real numbers $a, x$ and $y$
$$\begin{aligned} & -2x^{2} + y^{2} = 2a \\ & 3x^{2} - 2y^{2} = -6a \end{aligned}$$
what is the ratio $\dfrac{y}{x}$?
A) 1 B) $\sqrt{2}$ C) $\sqrt{3}$ D) 2 E) 3
turkey-yks 2024 Q10 Finding roots or coefficients of a quadratic using Vieta's relations View
Let $a$ and $b$ be positive real numbers. For each of the equations
$$\begin{aligned} & ax^{2} - 2x + b = 0 \\ & bx^{2} - 3bx + a = 0 \end{aligned}$$
the sum of roots is 1 more than the product of roots.
Which of the following could be the quadratic equation whose roots are $a$ and $b$?
A) $9x^{2} + 8x + 18 = 0$ B) $9x^{2} - 14x + 8 = 0$ C) $9x^{2} - 18x + 14 = 0$ D) $9x^{2} - 8x + 14 = 0$ E) $9x^{2} - 18x + 8 = 0$