RRB ALP CBT 1 2025 PYQs

Concept: Common letters share common digits (order may be jumbled).

1. Common letters D, A, H ↔ common digits 8, 6, 5.
2. DASH leftover: S ↔ 4; HADE leftover: E ↔ 2.

Short trick: The unique letter of a word gets the unique digit of its code.

Answer: (A) 2

Concept: Drop all symbols and count from the right.

1. Letters from the right end: C (1), G (2), T (3), B (4), Q (5).
2. Fifth from the right = Q.

Short trick: Only the right end matters — rewrite just the last few letters.

Answer: (C) Q

Concept: Vowel → next letter, consonant → previous letter.

1. C→B, E→F, R→Q, T→S, A→B, I→J, N→M.
2. New group: B F Q S B J M → B appears twice.

Short trick: B can come from A (vowel +1) and from C (consonant −1) — CERTAIN has both.

Answer: (D) B

Concept: Fix the definite days and work outward.

1. L = Saturday; two between G and L → G = Wednesday.
2. One between G and I, I not Monday → I = Friday.
3. Two between J and I → J = Tuesday; K just before J → K = Monday.
4. Thursday and Sunday remain for H and M; H not on the last day → H = Thursday.

Short trick: Use a 7-slot strip Mon–Sun and fill L, G, I, J, K in one pass.

Answer: (A) Thursday

Concept: Differences are powers of 2.

1. Differences: 1, 2, 4, 8 → next 16.
2. 46 + 16 = 62.

Short trick: Each difference doubles: 8 × 2 = 16.

Answer: (A) 62

Concept: Refractive index of a medium n = c (speed in air/vacuum) ÷ v (speed in the medium).

1. $n=\frac{c}{v}=1.33$ ⇒ $c=1.33v$.
2. So light in air is 1.33 times faster than in water; light slows down in water.

Short trick: Memory hook: 'n = c by v' — bigger n, slower light (denser medium).

Answer: (B) The speed of light in air is 1.33 times the speed of light in water.

Concept: A compound always contains its elements in a fixed ratio by mass (C : O = 12 : 32 = 3 : 8 in CO₂).

1. 36 g C = 3 × 12 g.
2. Oxygen = 3 × 32 = 96 g.

Short trick: Carbon tripled → oxygen tripled. (Law given by Proust.)

Answer: (A) 96 g

Concept: Dried neem leaves act as a natural insect repellent in stored grain.

1. Neem contains azadirachtin, which repels and disrupts the growth of storage pests (weevils, beetles, moths).
2. It is a cheap, chemical-free method used at home and on farms.

Short trick: Hook: Neem = natural pesticide (azadirachtin).

Answer: (D) Insect infestation

Concept: Gastric glands in the stomach wall secrete HCl, pepsin and mucus.

1. HCl makes the medium acidic and kills germs; it activates pepsin for protein digestion.
2. Mucus protects the stomach lining from the acid.

Short trick: 'Gastric' = stomach (Greek gaster).

Answer: (B) Stomach

Concept: Unicellular organisms: a single cell performs all life functions.

1. Amoeba, Paramoecium (protozoa) and Chlamydomonas (green alga) are unicellular.
2. Cycas is a multicellular gymnosperm plant (a 'living fossil').

Short trick: Hook: Cycas = a tree-like plant you can see — never one cell.

Answer: (D) Cycas

Concept: The region around a magnet in which its force can be detected is its magnetic field.

1. It is a vector quantity (magnitude + direction); SI unit tesla (T).
2. Field lines go from N to S outside the magnet; they are closest near the poles (strongest field).

Short trick: 'Field' = region of influence (like gravitational field, electric field).

Answer: (B) Magnetic field

Concept: All distances are measured from the pole/optical centre; distances in the direction of incident light are +, opposite are −.

1. The object is placed to the left, and light travels left → right.
2. So the object distance (u) of a real object is measured against the incident light → negative.

Short trick: Hook: 'u is always negative' for a real object in front of a mirror or lens.

Answer: (C) Negative when the object is real

Concept: Valency = combining capacity = electrons lost, gained or shared to complete the octet.

1. If valence electrons are 1–3, valency = number of valence electrons.
2. If the shell is nearly full (5–7), valency = 8 − valence electrons, e.g. Cl (7) → 1, O (6) → 2.

Short trick: Hook: 'Few → give, Many → take' — nearly full shells take electrons (8 − n).

Answer: (D) By the number of electrons needed to complete the octet

Concept: Under the National Quantum Mission (approved 2023, ₹6003.65 crore, DST) four Thematic Hubs were set up.

1. Quantum Computing – IISc Bengaluru.
2. Quantum Communication – IIT Madras (with C-DOT).
3. Quantum Sensing & Metrology – IIT Bombay.
4. Quantum Materials & Devices – IIT Delhi.

Short trick: Hook: 'Bengaluru computes, Madras talks, Bombay senses, Delhi builds.'

Answer: (B) Indian Institute of Science (IISc), Bengaluru

Concept: Article 40 (Part IV, DPSP): the State shall organise village panchayats as units of self-government.

1. Art. 50 – separation of judiciary from executive; Art. 60 – President's oath; Art. 30 – minorities' right to run educational institutions.
2. Panchayats got constitutional status by the 73rd Amendment, 1992 (Part IX).

Short trick: Hook: 'Panch-ayat at 40' — 40 = village self-rule (Gandhian principle).

Answer: (D) Article 40

Concept: Under CI the amount multiplies by the same factor in equal time intervals.

1. 1 → 3 in 3 years.
2. 3 → 9 is another ×3 → another 3 years.
3. Total = 3 + 3 = 6 years.

Short trick: If money becomes $k$ times in $t$ years, it becomes $k^n$ times in $nt$ years: $9=3^2$ → $2\times 3=6$ years.

Answer: (C) 6 years

Concept: If CP of $x$ items = SP of $y$ items, Profit% = $\frac{x-y}{y}\times 100$.

1. Let CP of 1 mango = ₹1 → CP of 25 = ₹25, SP of 25 = CP of 28 = ₹28.
2. Profit = 3 on 25.
3. Profit% = $\frac{3}{25}\times 100=12\mathrm{\%}$.

Short trick: (Bigger − smaller)/smaller = $\frac{28-25}{25}$ = 12%.

Answer: (A) 12%

Concept: SP = MP × (1 − discount) × (1 + VAT).

1. $x\times 0.35\times 1.44=378$.
2. $0.504x=378$.
3. $x=\frac{378}{0.504}=750$.

Short trick: Check options: 750 × 0.35 = 262.5; 262.5 × 1.44 = 378 ✓ (or $378÷1.44=262.5$, $262.5÷0.35=750$).

Answer: (C) 750

Concept: Equal quantities → add the fractions of each metal.

1. Alloy 1: A = $\frac{3}{5}$, B = $\frac{2}{5}$; Alloy 2: A = $\frac{5}{8}$, B = $\frac{3}{8}$.
2. Take LCM 40 of each: A = 24 + 25 = 49, B = 16 + 15 = 31.
3. Ratio = 49 : 31.

Short trick: Make totals equal (5 and 8 → 40): 3:2 = 24:16, 5:3 = 25:15 → add → 49:31.

Answer: (A) 49 : 31

Concept: Dividend = Divisor × Quotient + Remainder.

1. Divisor = 6 × 25 = 150.
2. Divisor = 10 × Quotient → Quotient = 15.
3. Dividend = 150 × 15 + 25 = 2275.

Short trick: Dividend must end in 5 (150 × q ends in 0, +25) → only 2275 among options.

Answer: (C) 2275