Q&A: practice questions with answers

Concept: Article 262 deals with inter-State river water disputes.

1. Parliament may by law provide for adjudicating such disputes — done through the Inter-State River Water Disputes Act, 1956 (tribunals like Cauvery, Krishna).
2. Parliament may also bar the Supreme Court and other courts from hearing such disputes.

Yaad rakhein: Article 263 = Inter-State Council — don't mix it with 262 (water).

Answer: (B) It can establish tribunals for water disputes and exclude Supreme Court's review power

Concept: Relative motion between source and listener changes the heard frequency.

1. Train approaching → waves crowd together → higher pitch.
2. Train moving away → waves spread out → lower pitch.
3. Refraction, diffraction and resonance do not need motion of the source.

Trick: Pitch change + moving source = Doppler, every time.

Answer: (B) Doppler effect

Concept: BNS (2023) separates organised crime (Sec. 111) from petty organised crime (Sec. 112).

1. Petty organised crime: group/gang acts like theft, snatching, cheating, pick-pocketing, illegal ticket selling, betting that create general insecurity.
2. Contract killing and drug trafficking come under organised crime; terrorism has its own section (Sec. 113).

Trick: 'Petty' = small, street-level gang crimes; serious crimes are just 'organised'.

Answer: (B) Theft carried out by a group or gang

Concept: Match each scheme to its purpose.

1. PKVY (2015) promotes organic farming through farmer clusters, with support for inputs, certification and marketing.
2. PM-KMY = pension for small farmers; Soil Health Card = soil nutrient testing; PM-KISAN = ₹6,000 yearly income support.

Trick: 'Paramparagat' = traditional farming = organic.

Answer: (A) Paramparagat Krishi Vikas Yojana (PKVY)

Concept: Check each statement, then the link.

1. NSWS (launched 2021) is an online portal where investors can apply for approvals from many ministries and states in one place → A correct.
2. It is a portal under DPIIT (Ministry of Commerce & Industry), not a ministry → R incorrect.

Trick: 'Single window' = one portal, not one ministry.

Answer: (C) A is correct, but R is incorrect

Concept: TTDI is released by the World Economic Forum.

1. In 2024 the USA ranked 1st, followed by Spain and Japan; most top-30 places went to rich nations of Europe and the Asia-Pacific.
2. India was 39th, the best among lower-middle-income countries.

Yaad rakhein: Options claiming low-income or developing nations 'dominate' rankings are rarely true.

Answer: (B) High-income countries from Europe and the Asia-Pacific region make up the majority of the top 30 TTDI rankings

Concept: The project is modelled on Africa's Great Green Wall.

1. Launched in 2023 by the Union Environment Ministry, it aims to restore degraded forest land and scrub around the Aravalli hills (Gujarat, Rajasthan, Haryana, Delhi).
2. The green belt is meant to check land degradation and the spread of the Thar desert eastward.

Trick: Name tells the place — Aravalli project is about Aravalli hills, not Himalaya or Indo-Gangetic belt.

Answer: (B) To rehabilitate degraded forest patches of the Aravalli hills

Concept: Ownership decides the sector: public, private, joint or cooperative.

1. Joint sector = government and private firms share ownership and management (e.g. early Maruti Udyog – GoI + Suzuki; Oil India Ltd).
2. Units run by local bodies are public sector; groups of producers/SHGs form the cooperative sector.

Yaad rakhein: Joint = Public + Private together.

Answer: (C) Industries jointly managed by both public and private sectors

Concept: Article 110 defines a Money Bill.

1. Under Article 110(3), if a doubt arises whether a Bill is a Money Bill, the Lok Sabha Speaker's decision is final.
2. Rajya Sabha has a Chairman (the Vice-President), not a Speaker — so option (D) is a trap.

Yaad rakhein: Money Bill: introduced only in Lok Sabha, with President's recommendation; Rajya Sabha can hold it for at most 14 days.

Answer: (B) Speaker of the Lok Sabha

Concept: Faint objects suffer most from artificial sky-glow.

1. Deep-sky objects (galaxies, nebulae, star clusters) give very dim light, which city sky-glow drowns out.
2. The Sun (sunspots), Moon (phases) and planets are bright, so they remain visible from cities.

Trick: Fainter the object, bigger the loss — choose the faintest option.

Answer: (B) Deep-sky objects

Concept: Rationalise: $\sqrt{x}-\sqrt{y}=\frac{x-y}{\sqrt{x}+\sqrt{y}}$.

1. $a=\sqrt{5}-\sqrt{3}=\frac{2}{\sqrt{5}+\sqrt{3}}\approx \frac{2}{3.97}\approx 0.50$.
2. $b=\sqrt{3}-\sqrt{2}=\frac{1}{\sqrt{3}+\sqrt{2}}\approx \frac{1}{3.15}\approx 0.32$.
3. $0.50>0.32\to a>b$.

Trick: For gaps of 1, $\sqrt{n+1}-\sqrt{n}$ shrinks as n grows; here a covers a gap of 2 (5 − 3) against b's gap of 1, so a is clearly bigger.

Answer: (C) a > b

Concept: Solve brackets first; dividing by a fraction = multiplying by its reciprocal.

1. Expression: $(\frac{1}{9}÷\frac{1}{3})÷(\frac{1}{15}+1-\frac{9}{10})$.
2. $\frac{1}{9}÷\frac{1}{3}=\frac{1}{9}\times 3=\frac{1}{3}$.
3. $\frac{1}{15}+1-\frac{9}{10}=\frac{2+30-27}{30}=\frac{5}{30}=\frac{1}{6}$.
4. $\frac{1}{3}÷\frac{1}{6}=\frac{1}{3}\times 6=2$.

Trick: Use LCM 30 for 15 and 10 at once; avoid decimals.

Answer: (D) 2

Concept: Use the colours whose additions are known to find the multiplier.

1. Let red, blue, green = $2k,3k,5k$.
2. $\frac{2k+10}{3k+10}=\frac{3}{4}\to 8k+40=9k+30\to k=10$.
3. New red = 30 = 3 parts → 1 part = 10 → new green = $6\times 10=60$.
4. Original green = 50 → added = $60-50=10$.

Trick: Blue − red is unchanged by equal additions: old gap = k, new gap = 1 unit, so unit = k; then $2k+10=3k\to k=10$.

Answer: (D) 10

Concept: Profit is shared in the ratio of capital × months.

1. In thousands — Rohit: $50\times 12=600$.
2. Ramesh: $100\times 6=600$.
3. Equal products → equal shares → Rohit = half of ₹20,000 = ₹10,000.

Trick: Half the money for double the time = equal investment.

Answer: (A) ₹10,000

Concept: Add capital × months for each period.

1. A = ₹50,000 → B = $50,000\times \frac{3}{5}=$ ₹30,000.
2. A: $50\text{k}\times 6+40\text{k}\times 6=540\text{k}$-months.
3. B: $30\text{k}\times 6+60\text{k}\times 6=540\text{k}$-months.
4. Ratio 1 : 1 → A's share = $\frac{90,000}{2}=$ ₹45,000.

Trick: Work in thousands (50, 40, 30, 60) — and since both get 6 months each time, just add: $50+40=90$ vs $30+60=90$.

Answer: (D) ₹45,000

Concept: Average of an AP = $\frac{\text{first term}+\text{last term}}{2}$.

1. Smallest 3-digit multiple of 19: $19\times 6=114$.
2. Largest: $19\times 52=988$ ($19\times 53=1007$).
3. Average = $\frac{114+988}{2}=\frac{1102}{2}=551$.

Trick: Average must itself be a multiple of 19 ($19\times 29=551$) — 552, 752, 352 fail.

Answer: (B) 551

Concept: Take each container = 100 units.

1. Milk = $30+50=80$ units out of 200.
2. Water = $200-80=120$ units.
3. Water% = $\frac{120}{200}\times 100=60\%$.

Trick: Equal volumes → average the water %: $\frac{70\%+50\%}{2}=60\%$.

Answer: (D) 60%

Concept: Form the bill before and after the swap.

1. Blue = ₹p/dozen, red = ₹2p; blue ordered = x dozen.
2. Original bill = $16p+xp$; delivered bill = $2xp+8p$.
3. $2x+8=1.4(16+x)\to 0.6x=14.4\to x=24$.
4. Red : Blue = 8 : 24 = 1 : 3.

Trick: Test option 1 : 3 ($x=24$): $16+24=40\to 48+8=56=1.4\times 40$ ✓.

Answer: (A) 1 : 3

Concept: Total cost must be recovered from the sellable items only.

1. Required SP = $900\times \frac{140}{100}=$ ₹1,260.
2. Only $300-90=210$ flowers can be sold.
3. So each must fetch $1260÷210=$ ₹6.

Trick: $\frac{1260}{210}=\frac{126}{21}=6$ — cancel the zero first.

Answer: (B) ₹6

Concept: Find CP from the loss, then the new SP after discount.

1. Z = 80% of CP → $\text{CP}=\frac{Z}{0.8}=1.25Z$.
2. New SP = $2.6Z\times 60\%=1.56Z$.
3. Profit = $0.31Z\to \frac{0.31}{1.25}\times 100=24.8\%$.

Trick: Take Z = 100: CP = 125, SP = 156 → profit $\frac{31}{125}=24.8\%$.

Answer: (B) 24.8%