Time and Work Questions

Multiple choice
  1. 5

  2. 10

  3. 8

  4. 15

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

A's rate is 1/35 per day, B's rate is 1/15 per day. Combined rate = 2/21 per day. Work done in 8 days = 16/21. Remaining work = 5/21. 60% of remaining = 3/21 = 1/7. Time for A to complete 1/7 = (1/7)/(1/35) = 5 days. The key is to first find the combined work rate, then calculate the remaining portion after 8 days.

Multiple choice
  1. 18 days

  2. 30 days

  3. 25 days

  4. 24 days

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

A's rate = 1/10 job/day, B's rate = 1/5 job/day. Together they do 3/10 per day. In 2 days: 6/10 = 3/5 done. Remaining: 2/5. A + C do 2/5 in 3 days, so A+C rate = 2/15 per day. C's rate = 2/15 - 1/10 = 1/30 job/day. C alone needs 30 days for full job, so 60% takes 18 days.

Multiple choice
  1. 21

  2. 20

  3. 24

  4. 25

  5. None of these / इनमे से कोई नही

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

Let total work be LCM(36,72,54)=216 units. A's rate=6/day, B's rate=3/day, C's rate=4/day. If work completes in D days: A works D-8 days (6D-48 units), C works D-12 days (4D-48 units), B works D days (3D units). Total: 13D-96=216, so 13D=312, D=24 days.

Multiple choice
  1. $4$
  2. $6$
  3. $8$
  4. $5$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let total work = 30 units (LCM of 30). A's efficiency = 30/30 = 1 unit/day. B is 25% more efficient than A, so B's efficiency = 1.25 units/day. C is 20% more efficient than B, so C's efficiency = 1.25 × 1.2 = 1.5 units/day. Work done by A and B in 10 days = (1 + 1.25) × 10 = 22.5 units. Remaining work = 30 - 22.5 = 7.5 units. Time for C alone = 7.5/1.5 = 5 days. This matches option D.

Multiple choice
  1. 18

  2. 12

  3. 15

  4. 20

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

A does 33.33% (1/3) of work in 10 days, so total work in 30 days. A's rate = 1/30 work/day. B does 20% (1/5) of work in 9 days, so total work in 45 days. B's rate = 1/45 work/day. Work done by A and B together in 8 days = 8(1/30 + 1/45) = 8(3/90 + 2/90) = 8(5/90) = 40/90 = 4/9 of work. Remaining = 5/9. C does 30% of remaining (5/9) in 10 days, so C does 0.3 × 5/9 = 1/6 of total work in 10 days. C's rate = 1/60 work/day. A and C together: 1/30 + 1/60 = 3/60 = 1/20 work/day, so they complete the work in 20 days.

Multiple choice
  1. 105, 210 and 70

  2. 56, 84 and 168

  3. 70, 10 and 105

  4. 84, 168 and 56

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

Let A, B, C's individual days be a, b, c. Combined rates: A+B = 1/70, B+C = 1/52.5 = 2/105, C+A = 1/42. Adding all three: 2(A+B+C) = 1/70 + 2/105 + 1/42. LCD of 70, 105, 42 is 210. So: 2(A+B+C) = 3/210 + 4/210 + 5/210 = 12/210 = 2/35. Thus A+B+C = 1/35. To find individual rates: (A+B+C) - (B+C) = A = 1/35 - 2/105 = 3/105 - 2/105 = 1/105, so A = 105 days. Similarly, B = 1/35 - 1/42 = 6/210 - 5/210 = 1/210, so B = 210 days. And C = 1/35 - 1/70 = 2/70 - 1/70 = 1/70, so C = 70 days. The answer (105, 210, 70) matches option A. However, the topic is incorrectly listed as 'Clocks & Calendars/Leap Year' when it should be 'Time and Work'.

Multiple choice
  1. Only II

  2. Only I

  3. From I and II

  4. Either from I or II

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

Both statements give equivalent information about the relationship between men and women's work rates. From I: (15 men + 12 women) = 12 days. From II: (10 men + 8 women) = 16 days. Both simplify to the same ratio, so either is sufficient.

Multiple choice
  1. 15 days 15 दिन

  2. 18 days 18 दिन

  3. 24 days 24 दिन

  4. 20 days 20 दिन

  5. 12 days 12 दिन

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

16 men complete work in 24 days, so 16 men's 1 day work = 1/24. 1 man's 1 day work = 1/(16×24) = 1/384. Similarly, 20 women complete in 24 days, so 1 woman's 1 day work = 1/(20×24) = 1/480. 8 men + 30 women's combined 1 day work = 8/384 + 30/480 = 1/48 + 1/16 = 1/48 + 3/48 = 4/48 = 1/12. Therefore they complete the work in 12 days, which is option E.

Multiple choice
  1. 38 days

  2. 54 days

  3. 44 days

  4. 56 days

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

Let m be the work done by one man in one day, and w be the work done by one woman in one day. From the first condition: 4m + 3w = 1/6 (since they complete 1 job in 6 days). From the second: 5m + 6w = 1/4. Solving these equations: Multiply first by 5: 20m + 15w = 5/6. Multiply second by 4: 20m + 24w = 1. Subtracting: 9w = 1/6, so w = 1/54. Therefore, one woman alone takes 54 days.

Multiple choice
  1. 6

  2. 9

  3. 4

  4. 8

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

A's 1 day work = 1/16, B's 1 day work = 1/12. Working together for 4 days, they complete 4(1/16 + 1/12) = 4(7/48) = 7/12 of the work. Remaining work = 5/12. B alone does this in (5/12)/(1/12) = 5 days. B worked for 4 days with A + 5 days alone = 9 days total.

Multiple choice
  1. 53 days

  2. 46 days

  3. 42 days

  4. 36 days

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

Let total work = 1 unit. A+B+C combined rate = 1/18. A's rate = 1/54. So B+C = 1/18-1/54 = 3/54-1/54 = 2/54 = 1/27. Given C is 3 times as productive as B, so C = 3B. Then B+3B = 4B = 1/27, so B = 1/108. A+B together = 1/54+1/108 = 2/108+1/108 = 3/108 = 1/36. Therefore, A and B together can build the wall in 36 days.

Multiple choice
  1. 2400 Rs

  2. 2000 Rs

  3. 1500 Rs

  4. 1600 Rs

  5. 1200 Rs

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

Ram's 1 day work = 1/15. Ram + Shyam's 1 day work = 1/10. So Shyam's 1 day work = 1/10 - 1/15 = (3-2)/30 = 1/30. This means Shyam alone takes 30 days. Their work ratio is (1/15):(1/30) = 2:1. So Shyam gets (1/3)×6000 = Rs 2000. Option B is correct.

Multiple choice
  1. 10 days

  2. 15 days

  3. 12 days

  4. 8 days

  5. 9 days

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

Let total work = 120 (LCM of 24,30,40). A's rate = 5/day, B's rate = 4/day, C's rate = 3/day. A+C work for 4 days: 8×4=32 work. Remaining work = 120-32=88. A+C work for last 6 days: 8×6=48 work. So B must have done 88-48=40 work. At 4/day, B worked for 40/4=10 days.

Multiple choice
  1. 7 days 7 दिन

  2. 8 days 8 दिन

  3. 12 days 12 दिन

  4. 9 days 9 दिन

  5. 10 days 10 दिन

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

Total work = LCM(10,12,15) = 60 units. Rates: A = 6, B = 5, C = 4 per day. If total days = d, A works 2 days (12 units), B works (d-3) days, C works d days. Equation: 12 + 5(d-3) + 4d = 60. Simplifying: 12 + 5d-15 + 4d = 60, so 9d = 63, d = 7 days.