Time and Work Questions

Multiple choice
  1. 15 days/दिन

  2. 18 days/दिन

  3. 14.4 days/दिन

  4. 12.8 days/दिन

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

Total work = 24×8×18 = 3456 man-hours. Two-thirds of work = 3456×(2/3) = 2304 man-hours. 30 workers at 6 hours/day do 180 man-hours per day. Days needed = 2304/180 = 12.8 days. This uses the standard work formula: Work = Men×Hours×Days, and we solve for the unknown days when the work quantity and workforce parameters change.

Multiple choice
  1. 24 days/दिन

  2. 30 days/दिन

  3. 32 days/दिन

  4. 27.5 days/दिन

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

Ram's efficiency: 1/40 work per day. Shyam's efficiency: 1/60 work per day. Combined efficiency = 1/40 + 1/60 = 5/120 = 1/24. Mohan's efficiency is 20% less = 80% of combined = 0.8 × 1/24 = 1/30. So Mohan alone takes 30 days. Verification: Combined (Ram + Shyam) do 1/24 per day. Mohan does 0.8 × 1/24 = 1/30 per day, so 30 days to complete.

Multiple choice
  1. 20 days/दिन

  2. 24 days/दिन

  3. 30 days/दिन

  4. 36 days/दिन

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

A completes work in 72 days, so A's rate = 1/72 per day. B is 20% more efficient, so B's rate = 1.2 × 1/72 = 1/60 per day. B completes 40% (0.4) of work: Time = 0.4 ÷ (1/60) = 24 days. Verify: In 24 days, B does 24/60 = 40% of work.

Multiple choice
  1. Rs. 120

  2. Rs. 150

  3. Rs. 165

  4. Rs. 160

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

Let woman's efficiency = w, boy's = b. From 2w + b = 1/14 and 2w + 4b = 1/8, subtracting gives 3b = 3/56, so b = 1/56. Then 2w = 1/14 - 1/56 = 3/56, giving w = 3/112. The ratio w:b = 3:2. If woman earns Rs. 240/day, boy earns 240 × 2/3 = Rs. 160/day. Option D is correct.

Multiple choice
  1. 20 days

  2. 24 days

  3. 18 days

  4. 15 days

  5. 12 days

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

Rajesh's 1 day work = 1/45. Suresh's 1 day work = 1/75. Mohan is 40% more efficient than Rajesh, so Mohan's 1 day work = (1/45) × 1.4 = 14/450 = 7/225. Combined work = 1/45 + 1/75 + 7/225. LCM = 225. Combined = (5+3+7)/225 = 15/225 = 1/15. Therefore, working together they complete the work in 15 days.

Multiple choice
  1. 12 days

  2. 13.5 days

  3. 14 days

  4. 16.5 days

  5. 15 days

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

Work rates: A = 1/10, B = 1/20, C = 1/40 per day. In a 3-day cycle: A + B + C = 7/40. After 5 cycles (15 days): 35/40 done, remaining = 5/40 = 1/8. Day 16 (A): 1/10 = 4/40, remaining = 1/40. Day 17 (B): needs only 1/40 of 1/20 = 0.5 day. Total = 16.5 days. Option D is correct.

Multiple choice
  1. 10

  2. 5

  3. 8

  4. 15

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

5 women's 1 day work = 1/6, so 1 woman's 1 day work = 1/30. 10 boys' 1 day work = 1/5, so 1 boy's 1 day work = 1/50. Combined: 5 boys + 3 women = 5/50 + 3/30 = 1/10 + 1/10 = 1/5 work per day. So they take 5 days.

Multiple choice
  1. 10 days

  2. 12 days

  3. 8 days

  4. 6 days

  5. 16 days

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

If A is 40% more efficient than B, then A:B efficiency ratio = 140:100 = 7:5. C does half the combined work of A and B, so C's efficiency = (7+5)/2 = 6 units. If C alone takes 36 days (C's total work = 6×36 = 216), then combined (A+B+C) efficiency = 7+5+6 = 18. Time = 216/18 = 12 days.

Multiple choice
  1. 12

  2. 9

  3. 15

  4. 18

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

Individual rates: A = 1/72, B = 1/24, C = 1/36 work per day. Combined rate = 1/72 + 3/72 + 2/72 = 6/72 = 1/12 per day. Time = 1 / (1/12) = 12 days. This is a standard work-rate problem where rates add when working together.

Multiple choice
  1. 5

  2. 6

  3. 7

  4. 8

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

Work is proportional to both men and days, so work = k × men × days. Setting up the ratio: [(p-1)(p+1)] / [(p+2)(p-1)] = 9/10. Simplifying: (p+1)/(p+2) = 9/10. Cross-multiplying: 10p + 10 = 9p + 18. Solving: p = 8. The key insight is that work varies directly with both manpower and time.

Multiple choice
  1. 60 days / दिन

  2. 45 days / दिन

  3. 40 days / दिन

  4. 30 days / दिन

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

Combined rate = 1/15 work per day. Shyam's rate = 1/20 work per day. Ram's rate = 1/15 - 1/20 = 4/60 - 3/60 = 1/60. Ram alone takes 60 days. The key is converting work time to rates and using subtraction.

Multiple choice
  1. 15 days / दिन

  2. 20 days / दिन

  3. 30 days / दिन

  4. 60 days / दिन

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

Let P=2x, Q=y, R=x (P is twice as efficient as R). P+Q = 1/12 work/day, Q+R = 1/15 work/day. Substituting: 2x+y = 1/12 and y+x = 1/15. Subtracting: x = 1/12 - 1/15 = (5-4)/60 = 1/60. So y = 1/15 - 1/60 = 4/60 - 1/60 = 3/60 = 1/20. Q's rate = 1/20, so Q alone takes 20 days. Verification: P=1/30, R=1/60, Q=1/20. P+Q=1/30+1/20=5/60=1/12 ✓, Q+R=1/20+1/60=4/60=1/15 ✓.

Multiple choice
  1. 10 days/दिन

  2. 20 days/दिन

  3. 11 days/दिन

  4. 15 days/दिन

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

Combined rate: X + Y = 1/12 work/day. X's rate = 1/20 work/day. So Y's rate = 1/12 - 1/20 = 1/30 work/day. When Y works half-day: effective rate = 1/20 + (1/30 × 1/2) = 1/20 + 1/60 = 4/60 = 1/15. Time = 15 days. Option D is correct.

Multiple choice
  1. 64 days

  2. 62 days

  3. 72 days

  4. 56 days

  5. None of these

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

P+Q complete 1/24 of work per day. P alone does 1/32 per day, so Q alone does 1/24 - 1/32 = 1/96 per day. In 8 days together, they complete 8/24 = 1/3 of the work. Remaining 2/3 work is done by Q alone at rate 1/96, taking (2/3) / (1/96) = 64 days.

Multiple choice
  1. Rs./रु.480

  2. Rs./रु.240

  3. Rs./रु.320

  4. Rs./रु.400

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

y = 1.25x, z = y/3 = x/3.75। A, B, C की दरें: 1/x, 1/1.25x, 3/x। संयुक्त दर = 1/z = 3.75/x = 1/x + 1/1.25x + C, से C की दर = 2/x। A की हिस्सेदारी = (1/x) / (3.75/x) = 4/15। A को मिलने वाला धन = 960 × 4/15 = 256 रु... पुनः गणना: z = y/3 = 5x/12। A, B, C दरें: 1/x, 4/5x, 12/5x। संयुक्त = 12/5x = 5/12x + 4/5x + C, से C = 109/60x। A का हिस्सा = (5/12x) / (12/5x) = 25/144। 960 × 25/144 = 166.67... कुछ गलत है।