If A is the father of B and C is the mother of B, what is the relationship between A and C?
A. Brother and Sister
B. Husband and Wife
C. Father and Daughter
D. Mother and Son
Correct Answer: B Given that A is the father of B and C is the mother of B, it implies that A and C are married, hence they are husband and wife.
Q2. [+2, -0.25]Science
Which gas is primarily responsible for the greenhouse effect?
A. Oxygen
B. Nitrogen
C. Carbon Dioxide
D. Argon
Correct Answer: C Step 1: The greenhouse effect is caused by certain gases trapping heat in Earth's atmosphere. CO is the most significant human-emitted greenhouse gas.
Step 2: While water vapor is the most abundant natural greenhouse gas, CO is the primary driver of anthropogenic (human-caused) climate change.
Shortcut Trick: 'CO = Climate Offender x 2'. Remember the main greenhouse gases with 'COW-FAN': CO, O (ozone), Water vapor, F-gases, Aerosols, NO (nitrous oxide), CH (methane). CO is #1 culprit because it stays in the atmosphere for 300-1000 years.
Key Composition of Atmosphere:
- Nitrogen (N): ~78% - NOT a greenhouse gas
- Oxygen (O): ~21% - NOT a greenhouse gas
- Argon (Ar): ~0.93% - NOT a greenhouse gas
- CO: ~0.04% - though tiny, it's the PRIMARY greenhouse gas due to its heat-trapping ability
Common Mistake: Students think oxygen or nitrogen cause the greenhouse effect since they make up 99% of the atmosphere. But greenhouse gases are trace gases that absorb and emit infrared radiation. O and N are transparent to infrared - they don't trap heat.
Q3. [+2, -0.25]Reasoning
If it is true that A > B and B > C, what can be concluded about A and C?
A. A = C
B. A < C
C. A > C
D. A and C are unrelated
Correct Answer: C Given A > B and B > C, by transitive property, it can be concluded that A > C.
Q4. [+2, -0.25]Science
What is the process called when an organism's genetic information is passed from one generation to the next?
A. Mutation
B. Genetic Drift
C. Hereditary
D. Evolution
Correct Answer: C Hereditary refers to the passing of traits or genetic information from parents to their offspring through the transmission of genetic information.
Q5. [+2, -0.25]Reasoning
Find the next number in the series: 2, 5, 8, 11, 14?
A. 15
B. 17
C. 18
D. 20
Correct Answer: B The series is formed by adding 3 to the previous term, hence the next number in the series would be: 14 + 3 = 17.
Q6. [+2, -0.25]Mathematics
A shopkeeper sells an item for Rs. 800 after giving a discount of 20% on its marked price. What is the marked price of the item?
A. Rs. 960
B. Rs. 1000
C. Rs. 900
D. Rs. 1020
Correct Answer: B Method 1 (Algebra): Let MP = x. 20% discount means SP = 80% of MP. So 0.80x = 800. x = 800/0.80 = Rs. 1000.
Method 2 (Unitary - Shortcut): If SP after 20% discount is Rs. 800, then 80% of MP = 800. So 1% of MP = 800/80 = 10. Therefore 100% (MP) = 10 x 100 = Rs. 1000.
Super Shortcut (1-Step): MP = SP x 100/(100 - discount%). MP = 800 x 100/80 = 800 x 5/4 = Rs. 1000. Just divide SP by (100 - discount%) and multiply by 100.
Verification: 20% of 1000 = 200. SP = 1000 - 200 = 800 OK
Common Mistake: Students often subtract 20% of 800 (160) and add it back, getting 960. Wrong! The discount is calculated on MP, not on SP. Always work with the formula: SP = MP x (100 - d%)/100.
Q7. [+2, -0.25]General Knowledge
Who was the captain of the Indian cricket team that won the 2011 ICC Cricket World Cup?
A. Sourav Ganguly
B. Rahul Dravid
C. MS Dhoni
D. Sachin Tendulkar
Correct Answer: C MS Dhoni was the captain of the Indian cricket team that won the 2011 ICC Cricket World Cup.
Q8. [+2, -0.25]Reasoning
Pointing to a photograph, a man said, "I have no brother or sister, but that man's father is my father's son." Whose photograph was it?
A. His own son
B. His father
C. His uncle
D. His nephew
Correct Answer: A Step 1: The man says 'I have no brother or sister' -> He is an only child.
Step 2: 'my father's son' - Since he has no siblings, 'my father's son' can only be HIMSELF.
Step 3: So the statement 'that man's father is my father's son' becomes: 'that man's father is ME'.
Step 4: Therefore, the man in the photograph is the son of the speaker. The photograph is of his son.
Shortcut Trick - Family Tree Method:
Draw a simple tree:
Speaker (no siblings) <- father
Speaker (only child) = 'my father's son'
That man's father = Speaker
-> That man = Speaker's son OK
Alternative Approach - Substitute Yourself:
Replace 'my father's son' with 'me' (since no siblings). The sentence becomes: 'that man's father is me.' If I am someone's father, that someone must be my child. Answer: his son.
Common Mistake: Many overcomplicate this by introducing cousins or uncles. The key phrase 'no brother or sister' eliminates all possibilities except the speaker himself. Always simplify 'my father's son' to 'me' when the person has no siblings.
Q9. [+2, -0.25]General Knowledge
Who was the founder of the Maurya Empire?
A. Bindusara
B. Ashoka
C. Chandragupta Maurya
D. Samudragupta
Correct Answer: C Step 1: The Maurya Empire was founded by Chandragupta Maurya around 322 BCE after he overthrew the Nanda dynasty with the guidance of his mentor Chanakya (also known as Kautilya or Vishnugupta).
Shortcut Trick: Remember the chronological order: 'Chandra -> Bindu -> Ashoka' (Grandfather -> Son -> Grandson). Chandragupta = founder; Bindusara = his son (expanded empire); Ashoka = grandson (greatest Maurya ruler).
Key Fact: Chanakya authored the Arthashastra and was instrumental in Chandragupta's rise to power. The Maurya Empire was the largest empire in ancient India.
Common Mistake: Students confuse Chandragupta Maurya (founder of Maurya) with Chandragupta I (founder of Gupta dynasty). Remember: Maurya = Chandragupta Maurya (322 BCE); Gupta = Chandragupta I (320 CE) - nearly 650 years apart!
Q10. [+2, -0.25]General Knowledge
Which river is the longest in India?
A. Ganga
B. Brahmaputra
C. Yamuna
D. Godavari
Correct Answer: A The Ganga is the longest river in India, stretching approximately 2,525 kilometers from its source in the Himalayas to its delta in the Bay of Bengal.
Q11. [+2, -0.25]Mathematics
What is the value of x in the equation 2x + 5 = 11?
A. 2
B. 3
C. 4
D. 5
Correct Answer: A To solve for x, subtract 5 from both sides of the equation: 2x = 11 - 5, 2x = 6, x = 6/2, x = 3. However, considering the given options and reevaluating the equation: 2x + 5 = 11, 2x = 11 - 5, 2x = 6, x = 6/2, x = 3, the correct option provided is actually 3, but based on the initial calculation, the mistake was in the calculation: 2x = 11 - 5, 2x = 6, x = 3, so the provided calculation in the solution was incorrect and the right step is: 2x = 11 - 5, 2x = 6, x = 3, which matches option B, not A, indicating an error in the initial solution provided.
Q12. [+2, -0.25]Mathematics
If the sum of the first 'n' odd natural numbers is 225, then what is the value of 'n'?
A. 10
B. 12
C. 15
D. 20
Correct Answer: C Step 1: Recall the formula - sum of the first n odd natural numbers = n^2. For example: 1 = 1^2, 1+3 = 4 = 2^2, 1+3+5 = 9 = 3^2, etc.
Step 2: Given sum = 225. So n^2 = 225.
Step 3: Take the square root: n = sqrt225 = 15.
Shortcut Trick: Learn the squares from 1 to 30. 225 is 15 squared - instantly tells you n = 15. No calculation needed if you know that 15^2 = 225 and 16^2 = 256.
Alternative Method: The nth odd number is (2n-1). Sum of first n odd numbers = n^2 (this is a fixed result - memorize it!).
Common Mistake: Some students use the formula for sum of n natural numbers (n(n+1)/2) instead of the odd number formula, getting the wrong answer. Always check: 'odd natural numbers' -> n^2; 'natural numbers' -> n(n+1)/2.
Q13. [+2, -0.25]Science
What is the process by which plants make their own food?
A. Respiration
B. Photosynthesis
C. Decomposition
D. Fermentation
Correct Answer: B Photosynthesis is the process by which plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy stored in glucose.
Q14. [+2, -0.25]General Knowledge
Who was the first Indian woman to win a medal at the Olympics?
A. P.T. Usha
B. Saina Nehwal
C. Mary Kom
D. Karnam Malleswari
Correct Answer: D Step 1: Karnam Malleswari won a bronze medal in weightlifting (69 kg category) at the 2000 Sydney Olympics.
Step 2: This made her the first Indian woman to win an Olympic medal.
Shortcut Trick: 'Malleswari' contains 'Mall' - think 'Mall-e-s-wari, Medal-e-First-wari'. Connect: Weightlifter -> heavy weights -> first woman to carry India's medal hopes. Also remember 2000 Sydney - the millennium Olympics.
Timeline for Indian Women at Olympics:
- 2000: Karnam Malleswari (Weightlifting) - FIRST ever
- 2012: Saina Nehwal (Badminton bronze)
- 2012: Mary Kom (Boxing bronze)
- 2016: P.V. Sindhu (Badminton silver)
- 2020: Mirabai Chanu (Weightlifting silver)
Common Mistake: Many confuse P.T. Usha ('Payyoli Express') as an Olympic medalist. She came 4th in 1984 by 1/100th of a second - famously missed the bronze!
Q15. [+2, -0.25]Reasoning
In a certain code, 'LION' is written as '12-9-15-14'. How is 'TIGER' written in that code?
A. 20-9-7-5-18
B. 20-10-8-6-19
C. 19-8-6-4-17
D. 21-9-7-6-18
Correct Answer: A Step 1: Each letter is replaced by its position in the English alphabet (A=1, B=2, ..., Z=26).
Step 2: For 'LION': L=12, I=9, O=15, N=14 -> 12-9-15-14 OK
Step 3: For 'TIGER': T=20, I=9, G=7, E=5, R=18 -> 20-9-7-5-18
Shortcut Trick: Learn the shortcut positions using the mnemonic 'EJOTY' - E=5, J=10, O=15, T=20, Y=25. From these anchor points, you can quickly find any letter. T=20, then I is 11 letters back from T, G is 13 back, etc.
Alternative Method: Instead of counting from A each time, use the reverse: A=1, B=2, C=3... Z=26. Practice with common words: TIGER -> T(20)-I(9)-G(7)-E(5)-R(18).
Common Mistake: Many students forget to count correctly around the middle of the alphabet (M/N). Double-check: G comes after F(6), so G=7, not 8.