Q&A: practice questions with answers

Concept: Write present ages as variables and form two equations.

1. Let Sujatha $=S$, Vanita $=V$. Then $5S=2V+5$.
2. After 4 years: $3(V+4)=5(S+4)-8\Rightarrow 3V=5S$.
3. So $3V=2V+5\Rightarrow V=5$, and $5S=15\Rightarrow S=3$.
4. $k=V-S=5-3=2$.

Trick: Substitute $5S$ from the first equation into the second – one step.

Answer: (A) $2$

Concept: $\text{Weighted average}=\frac{\sum (\text{marks}\times \text{weight})}{\sum \text{weights}}$.

1. $80\times 3+90\times 2=240+180=420$.
2. Total weight $=3+2=5$.
3. Weighted average $=\frac{420}{5}=84$.

Trick: Answer lies nearer 80 (bigger weight): $80+\frac{2}{5}\times 10=84$.

Answer: (A) $84$

Concept: $SI=\frac{P\times R\times T}{100}$; with equal $P$ and $T$, difference depends only on the rate difference.

1. Rate difference $=6.5\%-3.5\%=3\%$.
2. Difference $=\frac{200000\times 3\times 2}{100}$.
3. $=12000$.

Trick: Use the rate gap directly instead of finding both interests.

Answer: (D) ₹12,000

Concept: Correct total $=$ wrong total $+$ (correct values $-$ wrong values).

1. Wrong total $=30\times 55=1650$.
2. Correction $=(72-27)+(64-46)=45+18=63$.
3. Correct total $=1713$; average $=\frac{1713}{30}=57.1$.

Trick: Change in average $=\frac{63}{30}=2.1$ → $55+2.1=57.1$.

Answer: (D) $57.1$

Concept: Decode each symbol and build the family tree from P to T.

1. P ÷ Q: P is the father of Q.
2. Q + R: Q is the mother of R.
3. R – S: R is the brother of S, so S is Q’s daughter.
4. S × T: S is the wife of T.
5. So, T’s wife (S) → her mother (Q) → her father (P).

Trick: Read the chain backwards from T: wife → mother → father.

Answer: (A) Wife’s mother’s father

Concept: When people face the centre, "left" is clockwise and "right" is anticlockwise.

1. Fix D. B is immediately to the left of D; E is third to the left of D (D → B → _ → E).
2. Only C sits between A and E; the seat next to E on B’s side is not free for A, so C is the next seat after E and A after C.
3. The two remaining seats go to F and G; G is not a neighbour of E, so F sits between B and E and G sits between A and D.
4. From C moving to the right: E, F, B, D, then G → 4 people in between.

Trick: Place the most fixed person (D) first, then fill seats using “third to the left / immediate left” clues.

Answer: (A) Four

Concept: Compare positions of corresponding letters: here the pattern is $-3,-3,+1$.

1. KNR → HKS: $K-3=H,N-3=K,R+1=S$.
2. TGK → QDL: $T-3=Q,G-3=D,K+1=L$.
3. FXL → CUM: $F-3=C,X-3=U,L+1=M$ ✓.
4. LOQ → FJU fails at once ($L-6=F$).

Trick: Check only the first letter (−3) to cut options quickly: only F → C works.

Answer: (B) FXL : CUM

Concept: Look at the differences between consecutive terms.

1. $282-259=23,259-226=33$ → differences grow by 10.
2. Next difference 43: $226-43=183$
3. Check: $183-53=130,130-63=67$ ✓

Trick: Differences 23, 33, 43, 53, 63 – constant jump of 10.

Answer: (B) 183

Concept: Track the position with coordinates (East +x, North +y), turning left/right relative to the current direction.

1. Y(0, 0) → South 11 → (0, −11); left = East 45 → (45, −11).
2. Right = South 29 → (45, −40); right = West 18 → (27, −40).
3. Right = North 13 → (27, −27); right = East 29 → (56, −27).
4. Left = North 27 → Z(56, 0). Y is 56 km due West of Z.

Trick: Net N–S: $-11-29+13+27=0$, so the answer is purely East–West: $45-18+29=56$ km.

Answer: (C) 56 km towards the west

Concept: Write alphabet positions and check the gap within each cluster and between the clusters.

1. IK - PR: $9,11|16,18$ → $+2$ inside, $+7$ between.
2. HJ - OQ: $8,10|15,17$ and GI - NP: $7,9|14,16$ → same pattern.
3. OJ - NL: $15,10|14,12$ → pattern broken.

Trick: Check the first letters of the two clusters: +7 (I→P, H→O, G→N) but O→N is −1.

Answer: (A) OJ - NL

Concept: Each cluster follows $+2,+4$ inside; the pair relation is the same shift applied to every letter.

1. GIM: $7,9,13$ → $+2,+4$; VXB: $22,24,2$ (i.e. 28) → $+2,+4$.
2. # = SUY ($19,21,25$) and SUY → VXB is $+3$ on each letter.
3. So GIM $+3$ → J, L, P: % = JLP.

Trick: Find # first from the internal $+2,+4$ pattern, then apply the same shift (+3) to GIM.

Answer: (B) # = SUY , % = JLP

Concept: Find the operations between successive numbers in the given sets.

1. 12 - 14 - 16 - 20: $+2,+2,+4$; 14 - 16 - 18 - 22: $+2,+2,+4$.
2. 3 - 5 - 7 - 11: $+2,+2,+4$ ✓
3. 4 - 8 - 16 - 32 is $\times 2$; 13 - 15 - 17 - 32 ends $+15$; 19 - 20 - 22 - 44 is $+1,+2,\times 2$.

Trick: Only check the last step (+4) – it eliminates three options at once.

Answer: (A) 3 - 5 - 7 - 11

Concept: Write positions and check the steps from 1st → 2nd → 3rd letter.

1. MOJ: $13,15,10$ → $+2,-5$
2. GID: $7,9,4$ → $+2,-5$; IKF: $9,11,6$ → $+2,-5$
3. KMG: $11,13,7$ → $+2,-6$ ✗

Trick: Third letter is 3 places before the first in the group (M→J, G→D, I→F), but K→G is 4.

Answer: (C) KMG

Concept: Number positions 1 (top) to 7 (bottom) and place the fixed boxes first.

1. Three boxes above G → G at 4. One box between A and G → A at 2 or 6.
2. Three boxes between A and F with F above G → A = 6, F = 2; B just below F → B = 3.
3. Left: 1, 5, 7. C not next to A (6) → C = 1; D above E → D = 5, E = 7.
4. Boxes above D: C, F, B, G = 4.

Trick: Use the clue "F above G" to choose between the two cases for A instantly.

Answer: (D) 4

Concept: Change each digit by the rule (odd +1, even −2) and keep positions.

1. 1385762 → 1→2, 3→4, 8→6, 5→6, 7→8, 6→4, 2→0
2. New number: 2466840
3. 2nd from left = 4; 3rd from right = 8
4. Sum $=4+8=12$

Trick: Only transform the two digits needed: 2nd from left (3→4) and 3rd from right (7→8).

Answer: (D) 12

Concept: Draw the minimal Venn diagram: Chimpanzees ⊂ Gorillas ⊂ Monkeys, and Langurs completely outside Monkeys.

1. Since no monkey is a langur and all gorillas are monkeys, no gorilla is a langur → (I) "Some langurs are gorillas" is false.
2. All chimpanzees are monkeys, so some monkeys are certainly chimpanzees → (II) follows.

Trick: All A are B ⇒ Some B are A always follows (conversion).

Answer: (D) Only Conclusion (II) follows

Concept: Fix the days Monday (1) to Sunday (7) and place the definite clues first.

1. T = Sunday. Only three after R → R = Thursday.
2. P immediately after R → P = Friday; Q after P → Q = Saturday.
3. V < S < U in Mon–Wed → V = Monday, S = Tuesday, U = Wednesday.
4. Between S (Tue) and P (Fri): U, R → 2 people.

Trick: "Only three after" fixes the position immediately: $7-3=4$th day.

Answer: (A) Two

Concept: When two words share a letter, the code digit common to both codes belongs to that letter (codes may be in jumbled order).

1. RACE → 6259 and ANTS → 7941.
2. The only letter common to both words is A.
3. The only digit common to both codes is 9.
4. Hence A = 9.

Trick: Common letter ↔ common digit – no need to decode the full word.

Answer: (B) 9

Concept: Check the differences between consecutive terms.

1. Differences: $9-7=2,13-9=4,21-13=8,37-21=16$.
2. Differences double each time: $2,4,8,16$, next $32$.
3. Next term $=37+32=69$.

Trick: Differences in powers of 2 → keep doubling the gap.

Answer: (C) 69

Concept: Track each letter position of the clusters separately.

1. 1st letters: T, U, V, W → +1 → X.
2. 2nd letters: P, R, T, V → +2 → X.
3. 3rd letters: Y, S, M, G → −6 each → G − 6 = A (wrapping: G=7, 7 − 6 = 1 = A).
4. Answer cluster: XXA.

Trick: Write positions: Y25, S19, M13, G7 → step −6 → 1 = A.

Answer: (B) XXA