Q&A: practice questions with answers

Concept: Article 79: Parliament = President + Rajya Sabha + Lok Sabha.

1. 1 ✓ – Lok Sabha maximum 552 (530 States + 20 UTs + 2 nominated, as per the Constitution's original scheme).
2. 2 ✓ – Rajya Sabha is permanent; one-third members retire every 2 years.
3. 3 ✗ – the President is an integral part of Parliament.

Trick: Statement 3 is the classic trap – remove every option containing 3 (C, D); 1 is true → A.

Answer: (A) 1 and 2 only

Concept: Nitrous oxide (N₂O) is called laughing gas.

1. Inhaling N₂O causes mild euphoria; it is used as a light anaesthetic, e.g. by dentists.
2. NO₂ is a brown toxic gas; CO and SO₂ are poisonous pollutants.

Yaad rakhein: 'Nitrous' → laughing; N₂O also acts as a greenhouse gas.

Answer: (B) Nitrous oxide

Concept: 23½°N latitude crosses eight Indian states.

1. States: Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, West Bengal, Tripura, Mizoram → 1 ✓, 3 ✓.
2. 2 ✗ – Cancer is in the Northern Hemisphere; Capricorn (23½°S) is south of it, not north.

Trick: West→East order mnemonic: 'GRaM ChhaJ WeTMi' (Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, WB, Tripura, Mizoram).

Answer: (A) 1 and 3 only

Concept: UMANG = Unified Mobile Application for New-age Governance (launched 2017).

1. One app for many Central and State e-services – EPFO, pensions, gas booking, DigiLocker, etc.
2. It is not limited to banking or education, and is not social media.

Trick: 'Unified' in the name = many services in one place.

Answer: (B) Multiple government services

Concept: India's first interplanetary mission.

1. Mangalyaan (MOM) was launched by PSLV-C25 in November 2013 and reached Mars orbit in September 2014.
2. India was the first nation to reach Mars orbit in its maiden attempt.
3. Chandrayaan-1 → Moon; Aditya-L1 → Sun; AstroSat → space observatory.

Trick: Moon is not a planet – so Chandrayaan is lunar, not interplanetary.

Answer: (C) Mangalyaan

Concept: Inflation = prices of goods and services in general keep going up over a period.

1. When prices rise, one rupee buys fewer goods → purchasing power of money falls.
2. So (a) and (b) describe the same event; employment fall (D) is a separate issue.

Trick: Inflation ↑ = value of money ↓ – the two always move opposite.

Answer: (C) Both (a) and (b)

Concept: Each Plan had a key slogan/objective.

1. Fourth Plan (1969–74): its twin goals were growth with stability and moving steadily towards self-reliance.
2. It came after three Annual Plans (Plan Holiday 1966–69).

Yaad rakhein: Fifth Plan – 'Garibi Hatao'; Seventh – 'Food, Work and Productivity'.

Answer: (A) Fourth Plan (1969-74)

Concept: Queen of the Chowta dynasty who fought the Portuguese.

1. Rani Abbakka ruled Ullal, a port town near Mangaluru on the Tulu Nadu coast, in the 16th century.
2. She repeatedly defeated Portuguese attempts to control the port.

Yaad rakhein: She is honoured as 'Abhaya Rani' (the fearless queen).

Answer: (A) Ullal

Concept: Leader of India's Integrated Guided Missile Development Programme (IGMDP).

1. Dr A.P.J. Abdul Kalam headed IGMDP that produced Agni and Prithvi missiles.
2. He was the 11th President of India (2002–07).

Yaad rakhein: Bhabha – father of nuclear programme; Sarabhai – father of space programme.

Answer: (C) Dr A.P.J. Abdul Kalam

Concept: Light reaction makes O₂, ATP and NADPH; the Calvin cycle fixes CO₂.

1. 2 ✓ – photolysis of water in the light reaction releases O₂.
2. 3 ✓ – CO₂ is fixed into sugar in the Calvin (dark) cycle.
3. 1 ✗ – cyanobacteria photosynthesise without chloroplasts, so 'only' fails.

Trick: Absolute words ('only', 'always') in biology statements are usually false.

Answer: (B) 2 and 3 only

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

1. Aman: $60\times 10=600$; Priya: $90\times 8=720$ (in thousands).
2. Ratio 600 : 720 = 5 : 6 (total 11).
3. Priya = $55,000\times \frac{6}{11}=$ ₹30,000.

Trick: Profit 55,000 is divisible by 11 → 1 part = 5,000; Priya's 6 parts = 30,000.

Answer: (C) ₹30,000

Concept: Simplify from the lowest level upward: $x=3+\frac{1}{8+\frac{1}{6+\frac{1}{2}}}$.

1. $6+\frac{1}{2}=\frac{13}{2}$ → its reciprocal $\frac{2}{13}$.
2. $8+\frac{2}{13}=\frac{106}{13}$ → reciprocal $\frac{13}{106}$.
3. $x=3+\frac{13}{106}=\frac{318+13}{106}=\frac{331}{106}$.

Trick: x is a little more than 3, so the numerator must be just above $3\times 106=318$ → only $\frac{331}{106}$.

Answer: (A) $\frac{331}{106}$

Concept: Combined average = Σ(average × count) ÷ total count.

1. Take counts 3, 4, 5 (total 12).
2. Sum = $16\times 3+18\times 4+21\times 5=48+72+105=225$.
3. Average = $\frac{225}{12}=18.75\approx 18.7$.

Trick: Deviation from 18: $\frac{-2\times 3+0\times 4+3\times 5}{12}=\frac{9}{12}=0.75$ → 18.75.

Answer: (A) 18.7

Concept: Left = Initial $\times {(1-\frac{\text{removed}}{\text{total}})}^n$.

1. Fraction kept each time = $1-\frac{9}{54}=\frac{5}{6}$.
2. After 3 times: $54\times {\left(\frac{5}{6}\right)}^3=54\times \frac{125}{216}$.
3. = $\frac{125}{4}=31.25$ litres.

Trick: $\frac{54}{216}=\frac{1}{4}$, so answer = $125÷4$ – spot it in one line.

Answer: (C) 31.25 litres

Concept: Work backwards through each percentage layer.

1. Let eligible $=N$. Votes cast $=0.8N$; valid $=0.95\times 0.8N=0.76N$.
2. Winner = 60% of valid = $0.456N=22,800$.
3. $N=22,800÷0.456=50,000$.

Trick: Test options: $50,000\times 0.8\times 0.95\times 0.6=22,800$ ✓.

Answer: (C) 50,000

Concept: For the extra half-year, apply half the annual rate on the amount reached.

1. After 2 years: $20,000\times 1.1\times 1.1=$ ₹24,200.
2. Next 6 months at 5%: $24,200\times 1.05=$ ₹25,410.
3. $CI=25,410-20,000=$ ₹5,410.

Trick: Yearly CI: 2000, 2200, then 5% of 24,200 = 1210 → total 5,410.

Answer: (B) ₹5,410

Concept: $a:b=c:d$ means $ad=bc$.

1. Product of extremes = product of means: $(52-x)·(19-x)$ equals $(20-x)·(47-x)$.
2. Expand: $x^2-71x+988=x^2-67x+940\to 4x=48\to x=12$.
3. $x+5=17$.

Trick: Check: 40 : 35 = 8 : 7 ✓. Or use $x=\frac{ad-bc}{a+d-b-c}=\frac{988-940}{71-67}=12$.

Answer: (C) 17

Concept: Form one equation using old bill and new bill.

1. Blue = ₹p per dozen, black = ₹2p; blue dozens = b.
2. Original bill = $32p+bp$; new bill = $\mathrm{2bp}+16p$.
3. $2b+16=1.5(32+b)\to 0.5b=32\to b=64$. Ratio 16 : 64 = 1 : 4.

Trick: Option check with 1 : 4 (16 and 64): old $32+64=96$, new $128+16=144=1.5\times 96$ ✓.

Answer: (A) 1 : 4

Concept: Milk left = $100\times {(1-\frac{20}{100})}^2$.

1. Milk = $100\times {\left(\frac{4}{5}\right)}^2=64$ L.
2. Water = $100-64=36$ L.
3. Water : milk = 36 : 64 = 9 : 16.

Trick: Milk fraction ${\left(\frac{4}{5}\right)}^2=\frac{16}{25}$ → water $\frac{9}{25}$ → water : milk = 9 : 16 directly.

Answer: (B) 9 : 16

Concept: $(\sqrt{a}+\sqrt{b}{)}^2=a+b+2\sqrt{ab}$.

1. (B) $(\sqrt{5}+\sqrt{5}{)}^2=(2\sqrt{5}{)}^2=4\times 5=20$ ✓.
2. (A) $11+5+2\sqrt{55}-2\sqrt{55}=16$; (D) $7+3+2\sqrt{21}-2\sqrt{21}=10$.
3. (C) $5+2\sqrt{6}+2\sqrt{6}$ is not an integer.

Trick: $(\sqrt{a}+\sqrt{a}{)}^2=4a\to 4\times 5=20$ instantly.

Answer: (B) ($\sqrt{5}$ + $\sqrt{5}$)²