Multiple Problems
1. **Find the value of x in the given circle with center O and angle 50°**.
In a circle, the angle at the center is twice the angle at the circumference subtended by the same arc.
Formula: $$\text{Angle at center} = 2 \times \text{Angle at circumference}$$
Given angle at circumference = 50°
So, $$x = 2 \times 50 = 100°$$
2. **Find the quarterly rate to be paid if the annual rate is 8% on a house valued at 60000**.
Annual rate = 8%
Quarterly rate = $$\frac{8}{4} = 2\%$$ per quarter
Quarterly amount = $$60000 \times \frac{2}{100} = 1200$$
3. **Find the LCM of $$x(x+5)$$ and $$3x^2$$**.
Factorize:
$$x(x+5) = x(x+5)$$
$$3x^2 = 3 \times x \times x$$
LCM takes highest powers of each factor:
LCM = $$3 \times x^2 \times (x+5) = 3x^2(x+5)$$
4. **Find the value of y in the triangle with angles y° and 35° (isosceles triangle)**.
Sum of angles in triangle = 180°
Since two sides are equal, two angles are equal. Let the equal angles be y°.
So, $$y + y + 35 = 180$$
$$2y = 180 - 35 = 145$$
$$y = \frac{145}{2} = 72.5°$$
5. **Find the length of the train traveling at 72 km/h crossing a lamp post in 4 seconds**.
Speed = 72 km/h = $$72 \times \frac{1000}{3600} = 20$$ m/s
Length = speed \times time = $$20 \times 4 = 80$$ meters
6. **Find $$P(A \cap A')$$ given $$P(A) = \frac{2}{5}$$**.
Since $$A'$$ is the complement of $$A$$, $$A \cap A' = \emptyset$$ (empty set)
So, $$P(A \cap A') = 0$$
7. **Solve $$x^2 - x - 90 = 0$$ for $$x < 0$$**.
Use quadratic formula:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$ where $$a=1, b=-1, c=-90$$
$$x = \frac{1 \pm \sqrt{1 + 360}}{2} = \frac{1 \pm 19}{2}$$
Solutions: $$x = 10$$ or $$x = -9$$
Since $$x < 0$$, $$x = -9$$
8. **Find the value of x in triangle with sides 2x, 2x, and base 18 cm**.
Since two sides are equal, triangle is isosceles.
By triangle inequality:
$$2x + 2x > 18 \Rightarrow 4x > 18 \Rightarrow x > 4.5$$
No other info given, so value of $$x$$ must satisfy $$x > 4.5$$.
9. **Find the common ratio of geometric progression 72, 48, 32...**.
Common ratio $$r = \frac{48}{72} = \frac{2}{3}$$
10. **Find curved surface area of cylinder made from square of perimeter 56 cm**.
Square perimeter = 56 cm
Side length $$s = \frac{56}{4} = 14$$ cm
Cylinder height = side length = 14 cm
Cylinder circumference = side length = 14 cm
Radius $$r = \frac{14}{2\pi} = \frac{7}{\pi}$$ cm
Curved surface area $$= 2\pi r h = 2\pi \times \frac{7}{\pi} \times 14 = 2 \times 7 \times 14 = 196$$ cm²
11. **Find length of BD in quadrilateral with triangles ABC and BDE**.
Triangles ABC and BDE are similar (by angle-side-angle or given info).
Sides AB=5, AC=3, BE=12, DE=y, BD=x
From similarity:
$$\frac{AB}{BE} = \frac{AC}{DE} = \frac{BC}{BD}$$
Using $$\frac{5}{12} = \frac{3}{y}$$, solve for $$y$$:
$$y = \frac{3 \times 12}{5} = 7.2$$
Using $$\frac{5}{12} = \frac{x}{BC}$$, but BC not given, so insufficient info to find BD.
12. **Simplify $$\frac{5x}{2(x-1)} - \frac{3}{1-x}$$**.
Note $$1-x = -(x-1)$$
Rewrite second term:
$$\frac{3}{1-x} = \frac{3}{-(x-1)} = -\frac{3}{x-1}$$
Expression becomes:
$$\frac{5x}{2(x-1)} - \left(-\frac{3}{x-1}\right) = \frac{5x}{2(x-1)} + \frac{3}{x-1}$$
Find common denominator $$2(x-1)$$:
$$\frac{5x}{2(x-1)} + \frac{3 \times 2}{2(x-1)} = \frac{5x + 6}{2(x-1)}$$
13. **Find equation of line passing through (0, -2) and parallel to line $$3y - 6x = 5$$**.
Rewrite given line:
$$3y = 6x + 5 \Rightarrow y = 2x + \frac{5}{3}$$
Slope $$m = 2$$
Equation of line parallel with slope 2 passing through (0, -2):
$$y - (-2) = 2(x - 0) \Rightarrow y + 2 = 2x \Rightarrow y = 2x - 2$$
14. **Find base diameter of cone made from sector of radius 25 cm with height 24 cm**.
Slant height $$l = 25$$ cm (radius of sector)
Height $$h = 24$$ cm
Use Pythagoras to find radius $$r$$:
$$r = \sqrt{l^2 - h^2} = \sqrt{25^2 - 24^2} = \sqrt{625 - 576} = \sqrt{49} = 7$$ cm
Base diameter $$= 2r = 14$$ cm