Time and Work Questions

Multiple choice
  1. 30

  2. 10

  3. 20

  4. 15

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

A's 1 day work = 1/20, B's 1 day work = 1/30. A works for 10 days, completing 10/20 = 1/2 of the work. Remaining work = 1 - 1/2 = 1/2. B completes 1/2 work in (1/2) ÷ (1/30) = 15 days. Alternatively: total work = LCM(20,30) = 60 units. A does 3 units/day, B does 2 units/day. A completes 30 units in 10 days, leaving 30 units. B needs 30÷2 = 15 days.

Multiple choice
  1. 1021

  2. 1110

  3. 1621

  4. 1210

  5. None of these

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

Let work ratios be men:women:boys = 3:2:1 = 3x,2x,x per person daily. Day 1: (20*3x + 12*2x + 18*x) = 102x. Day 2: (20*3x + 8*2x + 12*x) = 88x. Day 3: (14*3x + 12*2x + 8*x) = 74x. Total: (102+88+74)x = 264x = 3960, so x=15. Day 3 work = 74*15 = 1110.

Multiple choice
  1. 15 days 15 दिन

  2. 18 days 18 दिन

  3. 17.5 days 17.5 दिन

  4. 22.5 days 22.5 दिन

  5. None of these इनमे से कोई नहीं

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

2 men = 5 women = 8 children in terms of work completion time. If 1 man completes work in 33 days, then 2 men complete it in 33/2 = 16.5 days. Work rate: 2 men do 1/16.5 work per day. So 5 women do 1/16.5 work per day, meaning 1 woman does 1/(16.5 × 5) = 1/82.5 work per day. Similarly, 8 children do 1/16.5 work per day, so 1 child does 1/(16.5 × 8) = 1/132 work per day. Combined rate of 1 man + 1 woman + 1 child = 1/33 + 1/82.5 + 1/132 = 0.0303 + 0.0121 + 0.0076 ≈ 0.05 work per day. Time = 1/0.05 = 20 days. Since 20 days is not among the options, the answer is 'None of these'.

Multiple choice
  1. A

  2. B

  3. C

  4. Both A and C

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

Calculate each person's time to complete full work: A does 1/2 in 20 days, so full work in 40 days. B does 10% in 10 days, so full work in 100 days. C does 1/3 in 13 days, so full work in 39 days. Comparing: C (39 days) < A (40 days) < B (100 days). C completes fastest.

Multiple choice
  1. 4 days

  2. 3 days

  3. 2 days

  4. 1 day

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

Child completes work in 20 days, so child's rate = 1/20. 4 men take double time of 5 children, so 4 men = 40 days, thus 1 man = 160 days. Each man is 2× faster than woman, so 1 woman = 320 days. Combined rate of 12 men + 10 children + 8 women = 12/160 + 10/20 + 8/320 = 3/40 + 1/2 + 1/40 = 1/2 + 1/10 = 5/10 + 1/10 = 6/10 = 3/5. Time = 1 ÷ 3/5 = 5/3 = 1.67 days ≈ 1 day.

Multiple choice
  1. 24 days

  2. 22 days

  3. 20 days

  4. 18 days

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

P+Q's combined rate = 1/12 work per day. In 5 days, they complete 5/12 of work. Remaining work = 7/12, which P completes alone in 14 days. So P's rate = (7/12) ÷ 14 = 1/24. Therefore P alone completes work in 24 days.

Multiple choice
  1. 4230

  2. 3320

  3. 3330

  4. 3460

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

From given data: A+B = 1/40, B+C = 1/50, A+C = 1/60. Adding all 3: 2(A+B+C) = 1/40 + 1/50 + 1/60. Solving gives efficiencies ratio A:B:C = 23:28:19. Wage difference between B and C is 900 for ratio difference of 9. Each ratio unit = 100. Total wages = (23+28+19) × 100 = 70 × 100 = 7000. But checking options, if total is 3330, ratio difference of 9 gives 900 wage difference with each unit = 100, matching.

Multiple choice
  1. 926

  2. 526

  3. 726

  4. 626

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

A's rate: 1/14 - 1/42 = 1/21; B's rate: 1/42; C's rate: 1/21 - 1/42 = 1/84. Work done: A=8/21, B=14/42=1/3, C=12/84=1/7. Total work ratio: 8/21:1/3:1/7 = 8:7:3. C's share = (3/18)×2541 = Rs 726.

Multiple choice
  1. 13

  2. 8

  3. 6

  4. 5

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

Let total work be 1 unit. A's rate is 1/9 per day and B's rate is 1/18 per day. Together their rate is 1/9 + 1/18 = 1/6 per day. Since A left 3 days before completion, B worked alone for those 3 days and completed 3/18 = 1/6 of the work. The remaining 5/6 was done together in (5/6) / (1/6) = 5 days. Total time = 5 + 3 = 8 days.

Multiple choice
  1. 5 days

  2. 6 days

  3. 7 days

  4. 8 days

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

Let child's capability = 2 units/day. Then woman = 4 units/day, man = 5 units/day. First scenario: 2 men + 3 women + 4 children = 10 + 12 + 8 = 30 units/day. In 10 days, they complete 300 units, so 10 hectares = 300 units, meaning 1 hectare = 30 units. Second scenario: 6 men + 4 women + 7 children = 30 + 16 + 14 = 60 units/day. For 16 hectares = 480 units. Days needed = 480/60 = 8 days.

Multiple choice
  1. $\( \frac{14}{3} \) days$
  2. $\( \frac{22}{3} \) days$
  3. $\( \frac{10}{3} \) days$
  4. $\( \frac{16}{3} \) days$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Individual rates: Ramos = 1/5 per day, James = 1/10 per day, Cristiano = 1/15 per day, Modric = 1/20 per day. Day 1 (Ramos + Modric): 1/5 + 1/20 = 5/20 = 1/4. Day 2 (James + Cristiano): 1/10 + 1/15 = 5/30 = 1/6. Two-day cycle completes 1/4 + 1/6 = 5/12 of work. After 4 days (2 cycles): 10/12 = 5/6 done. Day 5: 5/6 + 1/4 = 10/12 + 3/12 = 13/12 > 1, so work completes on day 5. Fraction of day 5 needed: 1 - 5/6 = 1/6, which takes (1/6)/(1/4) = 2/3 of day 5. Total days = 4 + 2/3 = 14/3 days.

Multiple choice
  1. 10 days

  2. 9 days

  3. 15 days

  4. 12 days

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

A's rate = 1/24 per day, B's rate = 1/40 per day. Working together for 8 days: 8(1/24 + 1/40) = 8(5/120 + 3/120) = 8(8/120) = 64/120 = 8/15 of work done. Remaining = 7/15. C completes 7/15 in 14 days, so C's rate = (7/15)/14 = 1/30 per day. A and C together: 1/24 + 1/30 = 5/120 + 4/120 = 9/120 = 3/40 per day. For 75% (3/4) of work: Time = (3/4)/(3/40) = (3/4) × (40/3) = 10 days. Option A is correct.

Multiple choice
  1. 15

  2. 14

  3. 12

  4. 18

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

Let man's efficiency be 3 units/day, woman's be 2 units/day. Together they do 5 units/day. In 66 days, total work = 66 × 5 = 330 units. Now 6 men and 2 women have combined efficiency = 6×3 + 2×2 = 18 + 4 = 22 units/day. Time = 330/22 = 15 days. The key is converting efficiency ratios to actual work units per day.