Comprehension

In the diagram,\[ \angle ABC = 90^\circ = \angle DCH = \angle DOE = \angle EHK = \angle FKL = \angle GLM = \angle LMN \]\[ AB = BC = 2CH = 2CD = EH = FK = 2HK = 4KL = 2LM = MN \]

Question: 1

The magnitude of \( \angle FGO \) =

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Place the points on a coordinate grid using the given lengths and right angles, then find the angle at G between GF and GO.
Updated On: Nov 4, 2026
  • \( 30^\circ \)
  • \( 45^\circ \)
  • None of these
  • \( 60^\circ \)
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The Correct Option is C

Solution and Explanation

Step 1: Choose a scale:
Let \(AB = BC = 4\). Then \(CH = CD = 2\), \(EH = FK = 4\), \(HK = 2\), \(KL = 1\), \(LM = 2\), \(MN = 4\).

Step 2: Coordinates:
Put B = (0, 0), C = (4, 0), H = (6, 0), K = (8, 0), L = (9, 0), M = (11, 0). The right angles give D = (4, 2), E = (6, 4), F = (8, 4). O lies on EH with DO perpendicular to EH, so O = (6, 2). From the figure, D, O, I and G lie on one horizontal line (the quadrilateral DEFG has DG horizontal), so G = (9, 2), directly above L.

Step 3: Angle at G:
Vectors from G: \(\vec{GF} = (-1, 2)\) and \(\vec{GO} = (-3, 0)\). The angle between GF and the horizontal line GO has \(\tan\theta = \dfrac{2}{1} = 2\), so \(\theta = \tan^{-1} 2 \approx 63.4^\circ\).

Step 4: Compare:
63.4 degrees is not 30, 45 or 60 degrees, so the answer is "None of these".

Final Answer:
The correct option is (3): None of these
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Question: 2

In the following diagram, \(\angle ABC = 90^\circ = \angle DCH = \angle DOE = \angle EHK = \angle FKL = \angle GLM = \angle LMN\) and \(AB = BC = 2CH = 2CD = EH = FK = 2HK = 4KL = 2LM = MN\).

What is the ratio of the areas of the two quadrilaterals ABCD to DEFG?

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Take CH as one unit and write every other length in that unit. Then find the area of the trapezium ABCD, and split DEFG into two triangles and a rectangle.
Updated On: Nov 4, 2026
  • 1 : 2
  • 12 : 7
  • 2 : 1
  • None of these
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The Correct Option is B

Solution and Explanation

Step 1: Put every length in terms of CH = u:
AB = BC = 2u, CD = u, EH = 2u, FK = 2u, HK = u, KL = u/2, LM = u, MN = 2u. All the marked angles are right angles, so AB, DC, EH, FK, GL and MN are vertical, and D, O, I, G lie on one horizontal line at height u above BM.

Step 2: Area of ABCD:
AB and DC are parallel (both vertical) with AB = 2u, DC = u, and the distance between them is BC = 2u. Area = \(\tfrac12(2u+u)\times 2u = 3u^2\).

Step 3: Area of DEFG in three pieces:
Triangle DOE: DO = CH = u and OE = EH - OH = 2u - u = u, so its area is \(\tfrac12 u^2\).
Rectangle OEFI: OI = HK = u and EO = FI = u, so its area is \(u^2\).
Triangle FIG: FI = FK - IK = u and IG = KL = u/2, so its area is \(\tfrac12\times u\times\tfrac u2 = \tfrac14 u^2\).
Area of DEFG = \(\tfrac12 u^2 + u^2 + \tfrac14 u^2 = \tfrac74 u^2\).

Step 4: Take the ratio:
\(\dfrac{ABCD}{DEFG} = \dfrac{3u^2}{\tfrac74 u^2} = \dfrac{12}{7}\), that is 12 : 7.

Final Answer:
The correct option is (2): 12 : 7
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Question: 3

How many numbers greater than 0 and less than a million can be formed with the digits 0, 7, and 8?

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When counting numbers with specific digits, consider each possible length and calculate the number of choices for each digit.
Updated On: Jul 4, 2026
  • 486
  • 1,084
  • 728
  • None of these
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The Correct Option is C

Solution and Explanation

We need to form numbers with the digits 0, 7, and 8. We can use the following cases for the number of digits: 1. **1-digit numbers:** We can choose 7 or 8 (not 0), so there are 2 options.
2. **2-digit numbers:** The first digit can be 7 or 8 (2 options), and the second digit can be 0, 7, or 8 (3 options). This gives \( 2 \times 3 = 6 \) options.
3. **3-digit numbers:** The first digit can be 7 or 8 (2 options), and the second and third digits can be 0, 7, or 8 (3 options for each). This gives \( 2 \times 3 \times 3 = 18 \) options.
4. **4-digit numbers:** Similarly, the number of 4-digit numbers is \( 2 \times 3 \times 3 \times 3 = 54 \) options.
5. **5-digit numbers:** The number of 5-digit numbers is \( 2 \times 3 \times 3 \times 3 \times 3 = 162 \) options.
6. **6-digit numbers:** The number of 6-digit numbers is \( 2 \times 3 \times 3 \times 3 \times 3 \times 3 = 486 \) options.
The total number of numbers formed is \( 2 + 6 + 18 + 54 + 162 + 486 = 728 \). Thus, the Correct Answer is 728.
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