Time and Work Questions

Multiple choice
  1. Only II

  2. Only I

  3. From I and II

  4. Either from I or II

  5. None of these.

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

Let m and w be the work done by 1 man and 1 woman per day. From statement I: 15m + 12w = 1/12, which simplifies to 5m + 4w = 1/36. This means 5 men and 4 women complete 1/36 of the work daily, so they need 36 days total. From statement II: 10m + 8w = 1/16, which simplifies to 5m + 4w = 1/32, giving 32 days. Each statement alone gives us the value of 5m + 4w, which is exactly what we need to find the time for 5 men and 4 women.

Multiple choice
  1. 204 days/दिन

  2. 336 days/दिन

  3. 225 days/दिन

  4. 284 days/दिन

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

1 man's 1 day work = 1/100. 10 men and 15 women's 1 day work = 1/6. So 10(1/100) + 15(1/w) = 1/6. Therefore: 1/10 + 15/w = 1/6. 15/w = 1/6 - 1/10 = (5-3)/30 = 2/30 = 1/15. So w = 15 × 15 = 225 days. One woman alone takes 225 days.

Multiple choice
  1. Only A

  2. Both B and C

  3. A, B and C

  4. Only C

  5. None of these

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

Pankaj and Abdul together receive Rs. 900 for a work. Pankaj works x days at rate 1/15 per day, Abdul completes the rest and receives Rs. 540. Pankaj gets Rs. 360. Abdul's payment being 1.5 times Pankaj's means he did 1.5 times the work: (1 - x/15) = 1.5(x/15), giving x = 6. With x = 6, Pankaj does 2/5 work, Abdul does 3/5 work in 10.8 days. Y = 18 works. Also if Y = 25, Abdul's rate = 1/25, Pankaj's = 1/37.5 (not 15). If Y = 30, Pankaj's = 1/45. The only valid pair from given options is x = 6, Y = 18, but the question asks which options are possible. Given the constraints, only option A (6, 18) is mathematically consistent.

Multiple choice
  1. 21 days 12 hours & 72:43

  2. 21 days 12 hours & 29:72

  3. 14 days 8 hours & 29:43

  4. 14 days 8 hours & 29:72

  5. None of these

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

Workers take 12, 18, 24, 36 days individually. Since efficiencies are descending (most efficient = least days), P=12 days, Q=18 days, R=24 days, S=36 days. Combined work per day = 1/12 + 1/18 + 1/24 + 1/36 = 6/72 + 4/72 + 3/72 + 2/72 = 15/72 = 5/24. Day 1: All work = 5/24, then P leaves. Day 2: Q + R + S work = 1/18 + 1/24 + 1/36 = 4/72 + 3/72 + 2/72 = 9/72 = 1/8 = 3/24, total = 8/24, Q leaves. Day 3: R + S work = 1/24 + 1/36 = 3/72 + 2/72 = 5/72, total = 29/72, S leaves. Remaining work = 1 - 29/72 = 43/72. Ratio completed:remaining = 29:43. R alone does 1/24 per day, so for 43/72 work: (43/72) / (1/24) = (43/72) × 24 = 43/3 = 14 days and 8 hours.

Multiple choice
  1. 12 days/दिन

  2. 10 days/दिन

  3. 24 days/दिन

  4. 8 days/दिन

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

Work rate problems: combined rate = sum of individual rates. A + B together: 1/6 work per day. A alone: 1/8 work per day. Therefore B's rate = (1/6 - 1/8) = (4/24 - 3/24) = 1/24 work per day. Time for B alone = 1/(1/24) = 24 days.

Multiple choice
  1. 220

  2. 550

  3. 440

  4. 330

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

Workers × Time = Constant. W × 20 = (W-110) × 30. Solving: 20W = 30W - 3300, so 10W = 3300, W = 330 workers.

Multiple choice
  1. 24 days

  2. 36 days

  3. 12 days

  4. 20 days

  5. 40 days

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

Ram's efficiency: 1/20 work per day. Mohan is 25% more efficient, so his rate = 1.25×(1/20) = 1/16 per day. In 4 days, Ram and Mohan complete: 4×(1/20 + 1/16) = 4×(4/80 + 5/80) = 4×(9/80) = 9/20 of work. Remaining work = 1 - 9/20 = 11/20. Sita completes 11/20 work in 22 days, so her rate = (11/20)/22 = 11/440 = 1/40 per day. Therefore, Sita alone takes 40 days to complete the entire job.

Multiple choice
  1. Rs 3200

  2. Rs 10400

  3. Rs 4200

  4. Rs 3600

  5. None of these

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

First calculate wage per unit: total wages ₹1484 divided by total work units (20×5 + 24×3 + 40×1 = 100 + 72 + 40 = 212) = ₹7 per unit. For 12 men, 20 women, 30 children: work units = 12×5 + 20×3 + 30×1 = 60 + 60 + 30 = 150 units. Amount = 150 × 7 = ₹1050. But this is weekly; for February 2017, we multiply by 4 weeks = ₹4200. The answer matches Option C.

Multiple choice
  1. $4(\frac{7}{15}) days$
  2. $5(\frac{5}{23}) days$
  3. $6(\frac{3}{19}) days$
  4. $4(\frac{13}{25}) days$
  5. None of these

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

A's rate: 1/15 work/day. B's rate: 1/12 work/day. C does 3/4 work in 18 days, so full work in 24 days, rate = 1/24. Combined rate = 1/15 + 1/12 + 1/24 = 8/120 + 10/120 + 5/120 = 23/120. Time = 120/23 = 5(5/23) days.

Multiple choice
  1. 800

  2. 1500

  3. 1000

  4. 1200

  5. 1800

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

Let woman's efficiency be 100%. Then man's efficiency = 150% (50% more than woman) and boy's efficiency = 80% (20% less than woman). Total efficiency = 100 + 150 + 80 = 330%. Wages are distributed in proportion to efficiency. Boy's share = (80/330) × 3300 = 800. The boy's efficiency is 80/330 of total, so his wage is the same fraction of total wages.

Multiple choice
  1. 35

  2. 15

  3. 22

  4. 18

  5. None of these

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

Let M, N, O's individual work rates be m, n, o work/day. M+N: 30 days, so m+n = 1/30. N+O: 24 days, so n+o = 1/24. O+M: 20 days, so o+m = 1/20. Adding all three: 2(m+n+o) = 1/30 + 1/24 + 1/20 = 1/8. So m+n+o = 1/16. In 10 days together, they complete 10/16 = 5/8 of work. Remaining work = 3/8. M's rate alone = (m+n+o) - (n+o) = 1/16 - 1/24 = 1/48. M needs (3/8)/(1/48) = 18 days.

Multiple choice
  1. 40

  2. 35

  3. 30

  4. 70

  5. None of these

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

Let initial workers = x. Work takes 4 days normally, so total work = x + (x-5) + (x-10) + (x-15) = 4x - 30. With attrition, takes 7 days: sum from first term to (x-30) = 7x - 105. Equating: 7x - 105 = 4(4x - 30). Solving gives x = 35.

Multiple choice
  1. 10

  2. 15

  3. 20

  4. 25

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

Let initial men = m, total work = W. Work done is constant: m×30 = (m+5)×20. So 30m = 20m + 100, giving 10m = 100, hence m = 10 men.

Multiple choice
  1. 50

  2. 75

  3. 82

  4. 110

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

Let initial men = m. Work is constant: m×100 = (m-10)×110. So 100m = 110m - 1100, giving 10m = 1100, hence m = 110 men.