Infosys Previous Year Questions in Aptitude and Reasoning
Aptitude Questions which are Asked in the infosys recently
🧮 Question:
Seats for Mathematics, Physics, and Biology in a school are in the ratio 5 : 7 : 8. They are increased by 40%, 50%, and 75% respectively. Find the new ratio of seats.
🧾 Step-by-Step Solution:
- Assume actual seats:
Mathematics = 500, Physics = 700, Biology = 800 - Increase each by given %:
Mathematics = 500 + 40% of 500 = 700
Physics = 700 + 50% of 700 = 1050
Biology = 800 + 75% of 800 = 1400 - New seats ratio:
700 : 1050 : 1400 - Simplify by dividing with 50:
14 : 21 : 28
✅ Final Answer: 14 : 21 : 28
Multiply each term of the original ratio by (100 + %increase):
(5×140) : (7×150) : (8×175) = 700 : 1050 : 1400 → 14 : 21 : 28
🧮 Question:
A, B and C can do a piece of work in 20, 30, and 60 days respectively. In how many days will A complete the work if he is assisted by B and C on every third day?
🧾 LCM Method — Step-by-Step Solution:
- Find LCM: LCM(20, 30, 60) = 60 (Take total work = 60 units).
- Daily rates (units/day):
A = 60 ÷ 20 = 3, B = 60 ÷ 30 = 2, C = 60 ÷ 60 = 1.
[formula: rate = total_work ÷ days] - Work in one 3-day cycle:
Day 1: A alone = 3 units
Day 2: A alone = 3 units
Day 3: A + B + C = 3 + 2 + 1 = 6 units
→ Total in 3 days = 12 units - Number of cycles to finish 60 units:
60 ÷ 12 = 5 cycles ⇒ Time = 5 × 3 = 15 days
✅ Final Answer: 15 days
Use LCM = 60 → rates 3,2,1 → 3-day work = 12 → 60/12 = 5 cycles → 15 days.
🧮 Question:
A bird flying 400 km covers the first 100 km at 100 km/h, the second 100 km at 200 km/h, the third 100 km at 300 km/h, and the last 100 km at 400 km/h. Find the average speed of the bird.
🧾 Step-by-Step Solution:
- Use average speed formula for unequal speeds over equal distances:
Average speed = Total distance / Total time - Time for each segment:
t₁ = 100/100 = 1 hr
t₂ = 100/200 = 0.5 hr
t₃ = 100/300 ≈ 0.3333 hr
t₄ = 100/400 = 0.25 hr - Total time: T = 1 + 0.5 + 0.3333 + 0.25 ≈ 2.0833 hr
- Average speed:
V_avg = Total Distance / Total Time = 400 / 2.0833 ≈ 192 km/h
✅ Final Answer: 192 km/h
For equal distances with different speeds, use: Average Speed = Total Distance / Total Time (don’t average the speeds directly).
🧮 Question:
Out of 17 applicants, there are 8 boys and 9 girls. Two persons are to be selected for the job. Find the probability that at least one of the selected persons will be a girl.
Options:
a) 25/34 b) 19/34 c) 21/34 d) 27/34
🧾 Step-by-Step Solution:
- Total ways to select 2 persons: C(17,2) = 17×16/2 = 136
- Complementary event (no girls = both are boys):
C(8,2) = 8×7/2 = 28
Probability of no girls = 28 / 136 = 7/34 - Probability of at least 1 girl:
1 - 7/34 = 27/34
✅ Final Answer: 27/34 (Option d)
For “at least one” probability → use complement method: P(at least 1) = 1 − P(none)
🧮 Question:
The ratio between the length and breadth of a rectangular park is 3 : 2.
A man cycling along the boundary at 12 km/hr completes one round in 8 minutes.
Find the area of the park (in sq. m).
Options:
(A) 15360 (B) 153600 (C) 30720 (D) 307200
🧾 Step-by-Step Solution:
- Assume: Length = 3x, Breadth = 2x
- Convert time to hours: 8 min = 8/60 = 2/15 hr
- Distance cycled = perimeter:
Distance = Speed × Time = 12 × 2/15 = 1.6 km = 1600 m - Perimeter formula: 2(L + B) = 2(3x + 2x) = 10x → 10x = 1600 → x = 160 m
- Find length and breadth: L = 3x = 480 m, B = 2x = 320 m
- Area of rectangle: Area = L × B = 480 × 320 = 153600 m²
✅ Final Answer: 153600 m² (Option B)
Use perimeter = 2(L+B) = distance cycled. Then solve for x using ratio L:B = 3:2.
🧮 Question:
Complete the comparison:
GANGA : HBOHB :: INDUS : ?
Options:
1. HMVCT 2. JOEVT 3. JOTVE 4. JOEEE
🧾 Step-by-Step Solution:
- Observe pattern in GANGA → HBOHB: Each letter is shifted +1 in alphabetical order.
- Apply same shift to INDUS:
I → J, N → O, D → E, U → V, S → T - Result: INDUS → JOEVT
✅ Final Answer: JOEVT (Option 2)
Look for letter shifts (addition/subtraction) or pattern in positions. Here, simple +1 shift works.
🧮 Question:
In a certain code language, 'ABCD' is coded as '2345' and 'PALE' is coded as '172136'. How will 'TOP' be coded in this language?
Options:
1. 201607 2. 211617 3. 201617 4. 201516
🧾 Step-by-Step Solution:
- Observe pattern: In ABCD → 2345, each letter is converted to a number corresponding to its position in the alphabet (+1).
A=1 → 2, B=2 → 3, C=3 → 4, D=4 → 5 - Alphabetical positions of letters in TOP:
T=20, O=15, P=16 - Following the same coding rule (two-digit or letter position-based):
TOP → T 20+1=21
O =15+1=16
P=16+1=17
✅ Final Answer: 211617 (Option 2)
Convert letters to their alphabetical positions and follow the given coding logic.
🧮 Question:
Study the information carefully and answer the given question.
In a certain code language:
- "Vinisha gifted white shirt" → "ani rad chr ogt"
- "they gifted white phone" → "ogt yet rad ose"
- "everybody have a white phone" → "lsn avn voy ose rad"
- "Vinisha have a laptop" → "cnc ani lsn avn"
What is the code for "shirt" in the given code language?
Options:
a) yet b) chr c) ogt d) ani
🧾 Step-by-Step Solution:
- Find the code for 'white': Appears in sentences 1,2,3 → common code = rad
- Find the code for 'gifted': Appears in sentences 1 & 2 → common code = ogt
- Find the code for 'Vinisha': Appears in sentences 1 & 4 → common code = ani
- Remaining code in sentence 1: chr → corresponds to shirt
✅ Final Answer: chr (Option b)
Use common code method: identify common words across sentences to match their codes.
🧮 Question:
A has 3 children. B is the brother of C and C is the sister of D. E, who is the wife of A, is the mother of D. There is only one daughter of the husband of E. What is the relation between D and B?
🧾 Step-by-Step Solution:
- B is brother of C → B = male
- C is sister of D → C = female, D = ?
- Only one daughter of A → Daughter = C → D = male
- So children of A: B, C, D → D and B are both male siblings
✅ Final Answer: Brother
Identify the only daughter first. Remaining male children are brothers. Then map relation.
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