RRB NTPC Undergraduate CBT 1 2025 PYQs

Concept: Final price $=\text{CP}\times (1+\frac{p_1}{100})(1+\frac{p_2}{100})$.

1. $\text{CP}\times 1.2\times 1.25=3000$.
2. $\text{CP}\times 1.5=3000\Rightarrow \text{CP}=2000$.

Trick: $\frac{6}{5}\times \frac{5}{4}=\frac{3}{2}$ ⇒ CP $=3000\times \frac{2}{3}$.

Answer: (D) ₹2,000

Concept: Let first type cost $x$; second costs $x+20$.

1. $3x+5(x+20)=420$.
2. $8x+100=420\Rightarrow 8x=320$.
3. $x=40$.

Trick: Option check: $x=40$ ⇒ $120+5\times 60=420$ ✓.

Answer: (A) ₹40

Concept: Difference of ratio parts corresponds to the given difference.

1. Bala − Amit $=7-5=2$ parts $=3600$.
2. 1 part $=1800$.
3. Chetan $=9\times 1800=16200$.

Trick: Unit method: find value of one part, multiply.

Answer: (B) ₹16,200

Concept: $(a-b{)}^2=(a+b{)}^2-4ab$.

1. $(a-b{)}^2={44}^2-4\times 228=1936-912=1024$.
2. $a-b=\sqrt{1024}=32$.
3. (Numbers are 38 and 6.)

Trick: Check: $38+6=44$, $38\times 6=228$ ✓.

Answer: (B) 32

Concept: Sum = average × count.

1. Sum of 5 numbers $=24\times 5=120$.
2. Given four: $18+20+25+27=90$.
3. Fifth $=120-90=30$.

Trick: Deviations from 24: $-6,-4,+1,+3$ total $-6$ ⇒ fifth $=24+6=30$.

Answer: (B) 30

Concept: Multiply the growth factors of each year.

1. $1.20\times 0.90=1.08$.
2. $1.08\times 1.15=1.242$.
3. Change $=24.2\%$ increase.

Trick: Base 100: $100\to 120\to 108\to 124.2$.

Answer: (B) 24.2% increase

Concept: Write all terms with base 2 and equate powers.

1. $2^{x+1}\times 2^{2(y-2)}=2^5$.
2. $x+1+2y-4=5\Rightarrow x+2y=8$.
3. $3y+2y=8\Rightarrow y=\frac{8}{5}=1.6$.

Trick: $4=2^2$ and $32=2^5$ — same base turns it into a linear equation.

Answer: (B) 1.6

Concept: Find A's present age, then use the ratio.

1. A now $=32-8=24$.
2. 4 parts $=24\Rightarrow 1$ part $=6$.
3. B $=5\times 6=30$ years.

Trick: B $=24\times \frac{5}{4}=30$.

Answer: (A) 30 years

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

1. AP 3, 7, 11, …, 51 (common difference 4, 13 terms).
2. Mean $=\frac{3+51}{2}=27$.

Trick: In any AP the average equals the middle term (7th term $=3+6\times 4=27$).

Answer: (D) 27

Concept: Write decimals as reduced fractions: $\text{LCM}=\frac{\text{LCM of numerators}}{\text{HCF of denominators}}$.

1. $12.4=\frac{62}{5}$; $7=\frac{7}{1}$, $1=\frac{1}{1}$.
2. LCM $=\frac{\text{LCM}(7,62,1)}{\text{HCF}(1,5,1)}=\frac{434}{1}=434$.
3. Check: $434÷7=62$, $434÷12.4=35$ ✓.

Trick: Always reduce the fraction ($\frac{124}{10}\to \frac{62}{5}$) before taking LCM.

Answer: (C) 434

Concept: Write each letter's position: within a group the pattern is $n,n-1,n-3$; the first letters move back by 5.

1. First letters: M(13) → H(8) → C(3) → X(24) → S(19), each $-5$ (wrapping after A).
2. Inside each group: M L J $=13,12,10$; H G E $=8,7,5$; X W U $=24,23,21$.
3. So S(19), R(18), P(16) → SRP.

Trick: Check the first letters only: they step back by 5, so the answer starts with S; then $-1,-2$ gives SRP.

Answer: (B) SRP

Concept: Draw the family tree from the given links.

1. Malti is Lakhan's wife; Deepak is their son.
2. Bablu is Deepak's brother and Amrita is Bablu's sister, so Amrita is also a child of Lakhan.
3. Nehal is Lakhan's brother → Nehal is Amrita's father's brother (uncle, chacha).

Trick: Brother of father = paternal uncle (chacha).

Answer: (A) Father's brother

Concept: Look for third number $=$ first $\times$ (2 $\times$ second) $+1$.

1. $(18,6,217)$: $18\times 12+1=216+1=217$ ✓
2. $(21,6,253)$: $21\times 12+1=252+1=253$ ✓
3. $(23,4,185)$: $23\times 8+1=184+1=185$ ✓
4. Others: $22\times 10+1=221\ne 220$, $23\times 12+1=277\ne 276$, $24\times 12+1=289\ne 287$.

Trick: 217 and 253 are 1 more than multiples of 18 and 21 – that '+1' reveals the rule.

Answer: (D) (23, 4, 185)

Concept: Treat the three parts of each term separately.

1. First letter: Q, O, M, K → $-2$ each → I.
2. Number: 18, 23, 28, 33 → $+5$ → 38.
3. Last letter: N, P, R, T → $+2$ each → V.

Trick: Split each term into letter–number–letter and run three mini-series.

Answer: (B) I38V

Concept: Position from left $=$ total $-$ position from right $+1$. Facing North, 'left' means towards the left end.

1. Vinayak from left $=25-13+1=13$th.
2. Utkarsh is 4 places to the left of Vinayak → $13-4=9$th from the left.

Trick: Left + right position $=$ total $+1$.

Answer: (B) 9th

Concept: A word common to two sentences takes the code common to both.

1. 'energy' appears in both: 'rest restores energy' and 'positive energy attracts'.
2. Common code in 'rk fj mg' and 'tw es fj' is 'fj'.

Trick: Match the common word with the common code.

Answer: (D) fj

Concept: Scan for the pattern Even – Even – Odd and count the middle digit.

1. Position 4: 6 → 6 before (even), 3 after (odd) ✓
2. Position 13: 4 → 8 before, 3 after ✓
3. Position 21: 6 → 4 before, 1 after ✓
4. No other even digit has an even neighbour before and an odd one after.

Trick: First mark every odd digit, then look only at the digit just before it.

Answer: (C) Three

Concept: Compare the letter positions within each cluster.

1. TL – NX: $20\to 12$ ($-8$), $14\to 24$ ($+10$).
2. NF – HR: $14\to 6$ ($-8$), $8\to 18$ ($+10$); JB – DN: $10\to 2$ ($-8$), $4\to 14$ ($+10$).
3. DV – PH: $4\to 22$ ($+18$), $16\to 8$ ($-8$) – pattern differs.

Trick: Also, first letters T→N, N→H, J→D drop by 6, but D→P does not.

Answer: (D) DV - PH

Concept: Find the gaps between consecutive letters.

1. LIH: $12\to 9\to 8$ ($-3,-1$); YVU: $25\to 22\to 21$ ($-3,-1$); RON: $18\to 15\to 14$ ($-3,-1$).
2. CAY: $3\to 1\to 25$ ($-2,-2$ with wrap-around) – different.

Trick: Write the alphabet numbers once; the three matching clusters show the same gaps.

Answer: (B) CAY

Concept: Differences are perfect squares $1^2,2^2,3^2,4^2,5^2$.

1. $56+1=57$
2. $57+4=61$
3. $61+9=70$, $70+16=86$, $86+25=111$ ✓

Trick: Check from the end: $111-86=25$, $86-70=16$ → squares, so $?=70-9$.

Answer: (B) 61