Time and Work Questions

Multiple choice
  1. 22(3/4) days

  2. 25(1/2) days

  3. 24(1/2) days

  4. 22(1/2) days

  5. 23(1/2) days

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

P is thrice as efficient as Q, so P takes 1/3 the time Q takes. If Q takes x days, P takes x/3 days. Difference: x - x/3 = 60, so 2x/3 = 60, x = 90. Q takes 90 days, P takes 30 days. Together: 1/30 + 1/90 = 4/90 = 2/45. Time = 45/2 = 22.5 days. Option D is correct.

Multiple choice
  1. 15 days 15 दिन

  2. 12.5 days 12.5 दिन

  3. 18 days 18 दिन

  4. 24 days 24 दिन

  5. None of these इनमे से कोई नहीं

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let C's rate=1 unit/day. Then A=3 units/day (thrice C), B=1.5 units/day (half A). B+C combined rate=2.5 units/day. In 15 days: 2.5×15=37.5 units total work. A alone: 37.5÷3=12.5 days.

Multiple choice
  1. 1320 Rs

  2. 1280 Rs

  3. 1550 Rs

  4. 1700 Rs

  5. None of these इनमे से कोई नहीं

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Work rates: A = 1/7 per day, B = 1/12 per day, C = 1/14 per day. Combined A+B+C+D complete 1/2 work per day. A+B+C = 1/7+1/12+1/14 = 12/84+7/84+6/84 = 25/84 per day. So D's rate = 1/2-25/84 = 42/84-25/84 = 17/168. D's share = (17/168)/(1/2) = 17/84 of total work. Payment: (17/84)*4200 = 17*50 = 850, so D's share = 4200/4.9 = 1700.

Multiple choice
  1. Rs.1200

  2. Rs.3000

  3. Rs.3600

  4. Rs.2400

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total work = LCM(8,12,4) = 720 units. Ramu's rate = 90 units/day, Shyamu's rate = 60 units/day, combined rate with Raju = 180 units/day. Raju's rate = 180 - 90 - 60 = 30 units/day. In 4 days, Raju does 120 units. Share = (120/720) × 7200 = Rs. 1200. Option A is correct.

Multiple choice
  1. 18 days 18 दिन

  2. 8 days 8 दिन

  3. 22 days 22 दिन

  4. 12 days 12 दिन

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Find individual work rates: 24 men in 16 days → 1 man's rate = 1/384 per day. 8 women in 72 days → 1 woman's rate = 1/576 per day. 24 children in 32 days → 1 child's rate = 1/768 per day. Combined rate of 10 men + 15 women + 24 children = 10/384 + 15/576 + 24/768 = 5/192 + 5/192 + 1/32 = 1/12 per day. So work completes in 12 days.

Multiple choice
  1. 26

  2. 14

  3. 34

  4. 27

  5. 24

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Let man's rate = 1/(T+16), woman's rate = 1/(T+36). Combined rate = 1/T. So 1/(T+16) + 1/(T+36) = 1/T. Multiplying by T(T+16)(T+36): T(T+36) + T(T+16) = (T+16)(T+36). T² + 36T + T² + 16T = T² + 52T + 576. 2T² + 52T = T² + 52T + 576. T² = 576, T = 24 (positive). Option E is correct.

Multiple choice
  1. 24 days

  2. 20 days

  3. 21 days

  4. 19 days

  5. 23 days

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A's work rate is 1/16 per day, B's is 1/24 per day. Together for 2 days: 2×(1/16 + 1/24) = 2×(5/48) = 5/24. Remaining work: 1 - 5/24 = 19/24. B completes this alone in (19/24) ÷ (1/24) = 19 days, which matches option D.

Multiple choice
  1. 12

  2. 10

  3. 15

  4. 16

  5. None of these इनमे से कोई नही|

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total work = 10 × 12 × 7 = 840 person-hours. Let required days be d. Then 14 × d × 6 = 840, so d = 840/(14 × 6) = 840/84 = 10 days.

Multiple choice
  1. Rs.80

  2. Rs.85

  3. Rs.70

  4. Rs.75

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Annu's 1-day work = 1/6, Bhanu's 1-day work = 1/8. Working together for 3 days, they complete (1/6 + 1/8) × 3 = 7/8 of the work. Charu completes the remaining 1/8 in 3 days, so Charu's 1-day work = 1/24. Charu's 3-day contribution = 3/24 = 1/8 of work. Charu's share = 1/8 × 600 = Rs. 75.

Multiple choice
  1. 65.25

  2. 66.67

  3. 67.5

  4. 65.83

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total work = 15 men × 120 days = 1800 man-days. Also 25 women × 120 days = 3000 woman-days. So 15 men = 25 women, 1 man = 25/15 = 5/3 women. 20 men work for 30 days: work done = 20 × 30 = 600 man-days. Remaining work = 1800 - 600 = 1200 man-days = 1200 × (5/3) = 2000 woman-days. 30 women complete this in: 2000/30 = 66.67 days. Correct answer is option B.

Multiple choice
  1. 27 days 27 दिन

  2. 36 days 36 दिन

  3. 32 days 32 दिन

  4. 40 days 40 दिन

  5. None of These इनमे से कोई नहीं

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

P's efficiency = 1/21 work per day. Q is 25% less efficient, so Q's efficiency = (1/21) × (3/4) = 1/28. In 7 days, Q completes 7/28 = 1/4 of work. Remaining 3/4 is done by R in 27 days, so R's rate = (3/4)/27 = 1/36. R alone takes 36 days.

Multiple choice
  1. 42

  2. 45

  3. 48

  4. 50

  5. None of these इनमे से कोई नहीं

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A works for 4 days alone: 4/30 done. A and B together finish remaining 26/30 in 16 days, so their combined rate is (26/30)/16 = 13/240 per day. A's rate is 1/30 = 8/240. B's rate = 13/240 - 8/240 = 5/240 = 1/48. B alone takes 48 days.

Multiple choice
  1. 10

  2. 9

  3. 8

  4. 6

  5. None of these इनमे से कोई नहीं

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total work = 12 × 32 × 8 = 3072 person-hours for 320m. Rate = 3072/320 = 9.6 person-hours per meter. For 250m at 10 hours/day with 40 persons: days = (250 × 9.6)/(40 × 10) = 2400/400 = 6 days. Option A (10) ignores the increased workforce and hours.

Multiple choice
  1. 6 days 6 दिन

  2. 5 days 5 दिन

  3. 7.2 days 7.2 दिन

  4. Cann't be determined निर्धारित नहीं कर सकते

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Let 1 woman's work = w, 1 man's work = m per day. 6w + 6m = 1/6 (total work per day). 9w = 1/10, so w = 1/90. Substituting: 6(1/90) + 6m = 1/6, so 1/15 + 6m = 1/6. Thus 6m = 1/6 - 1/15 = 5/30 - 2/30 = 3/30 = 1/10, so m = 1/60. 15 men: 15m = 15/60 = 1/4 per day, so 4 days needed. Options A (6), B (5), C (7.2) are all wrong. 4 days is not listed, so E (None of these) is correct. D is incorrect because we CAN determine it.

Multiple choice
  1. 5 days 5 दिन

  2. 4 days 4 दिन

  3. 7 days 7 दिन

  4. 6 days 6 दिन

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Let A work for d days. Work done by both in d days = d(1/24 + 1/36) = d(5/72). Work done by B alone for 16 days = 16/36 = 4/9. Total work: d(5/72) + 4/9 = 1. Solving: 5d/72 + 32/72 = 72/72, so 5d = 40, d = 8. But wait, rechecking: A's rate = 1/24, B's rate = 1/36. Combined work for d days: d(1/24 + 1/36) = d(5/72). B alone for 16 days: 16/36 = 4/9. 5d/72 + 4/9 = 1 gives 5d/72 = 5/9, so d = 8. The answer 8 is not in options A-D.