Time and Work Questions

Multiple choice
  1. Only I

  2. Only II

  3. Both I and II

  4. Neither I nor II

  5. Either I or II

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

Statement I only relates Q and R's time with Q = R - 10, which gives no information about P. Statement II gives two relationships: R = P + 20 and P = Q - 10, which can be combined to get R = Q + 10. Combining both statements gives Q = R - 10 and R = Q + 10, which are consistent. However, we have three variables (P, Q, R) with only two independent equations. Without absolute values or total work, we cannot determine P's exact number of days.

Multiple choice
  1. 10

  2. 15

  3. 18

  4. 12

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

A, B, and C work at rates of 1/35, 1/42, and 1/28 per day respectively. If A leaves 2 days early, A works (T-2) days while B and C work T days: (T-2)/35 + T/42 + T/28 = 1. Solving gives 6(T-2) + 5T + 7.5T = 210, so T = 12 days.

Multiple choice
  1. Any two

  2. All three together are sufficient

  3. I and III

  4. II and III

  5. II and I or III

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

Statement II: Rakesh and Arjun have equal efficiency, and together complete work in 10 days, so each does 1/20 per day. Statement III: Vimal working 10 days completes 60%, so Vimal's rate = 60%/10 = 6% per day. Statement I gives days worked: Rakesh=8, Arjun=6, Vimal=5. Using rates from II and III: Rakesh's share = 8*(1/20) = 40%, Arjun's share = 6*(1/20) = 30%, Vimal's share = 5*6% = 30%. All three statements are needed.

Multiple choice
  1. 25 days/ दिन

  2. 30 days/ दिन

  3. 40 days/ दिन

  4. 20 days/ दिन

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

Let P take x days, Q takes (x-10) days, R takes (x-6) days. P+Q combined rate = 1/x + 1/(x-10). R alone takes (x-6) days, so R's rate = 1/(x-6). Given: P+Q can do work in half time of R, so 2(1/x + 1/(x-10)) = 1/(x-6). Solving: 2((2x-10)/x(x-10)) = 1/(x-6), which gives x = 30 days.

Multiple choice
  1. 12 : 13

  2. 9 : 13

  3. 13 : 12

  4. 13 : 9

  5. None of these

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

Efficiency is inversely proportional to time when wages are equal. Total wages paid: A = 13 × 9 = 117, B = 16 × 12 = 192. Efficiency ratio = (wage/time) = 117/9 : 192/12 = 13 : 12. Option C is correct. Option A (12:13) is the inverse ratio - a common trap.

Multiple choice
  1. 12

  2. 17

  3. 10

  4. 15

  5. None of these

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

A's 1-day work = 1/36, B's 1-day work = 1/40. Let they work together for x days, then A works alone for 17 days. Total work: x(1/36 + 1/40) + 17/36 = 1. Solving: x(19/360) = 19/36, so x = 10 days. Option C is correct. Option B (17) is the time A worked alone - a common trap.

Multiple choice
  1. Any two

  2. I and II or III

  3. III and I or II

  4. All three together are not sufficient

  5. All three together are sufficient

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

All three statements together are sufficient to find Akash's individual completion time. From Statement III, P = 0.8A. Combined with Statement II (A + P = 1/60), we get A = 1/108 per day. Using Statement I (A + K = 1/52), we solve for K = 1/52 - 1/108 = 7/756, giving Akash's time as 108 days. Each statement is necessary - eliminating any one leaves the system unsolvable.

Multiple choice
  1. 24 days

  2. 36 days

  3. 20 days

  4. 18 days

  5. None of these

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

Work rates: A does 1/18 per day, B does 1/24 per day, C does 1/36 per day. In one 3-day cycle (A+B+C), they complete 1/18 + 1/24 + 1/36 = 4/72 + 3/72 + 2/72 = 9/72 = 1/8 of the work. So 8 cycles (24 days) are needed. Working 8 days each: A does 8/18, B does 8/24, C does 8/36. Total = 8/18 + 8/24 + 8/36 = 4/9 + 1/3 + 2/9 = 4/9 + 3/9 + 2/9 = 9/9 = 1 (complete).

Multiple choice
  1. I alone is sufficient while II alone is not sufficient.

  2. II alone is sufficient while I alone is not sufficient.

  3. Either I or II is sufficient.

  4. Neither I nor II is sufficient.

  5. Both I and II together are sufficient.

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

Statement I: A:B efficiency = 3:2. Let A = 3 units/day, B = 2 units/day. A + C: 24 days, so combined rate = 1/24. Let C = c units/day. A + C = 3 + c. B + C: 75% work in 12 days, so rate = 0.75/12 = 1/16. B + C = 2 + c = 1/16, giving c = 1/16 - 2 = -31/16. This gives C = 31/16 units/day. A + C = 3 + 31/16 = 79/16, which matches 1/24 work rate (since 79/16 × 24 = 118.5 ≠ 1). Wait, let me redo. If A + C complete work in 24 days, their combined rate is 1/24 work per day. B + C complete 75% in 12 days, rate = 3/4 × 1/12 = 1/16. With B = 2, C = 1/16 - 2 = -31/16. A + C = 3 + (-31/16) = 17/16. If this completes in 24 days, total work = 24 × 17/16 = 25.5. A alone: 25.5/3 = 8.5 days. Statement I is sufficient. Statement II gives information about B's efficiency but doesn't provide absolute work quantities or time relationships to determine A's individual time. Statement II alone is insufficient.

Multiple choice
  1. Rs. 420/ 420 रूपये

  2. Rs. 480/ 480 रूपये

  3. Rs. 560/ 560 रूपये

  4. Rs. 500/500 रूपये

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

Let 1 man's work = m, 1 boy's work = b. From equations: 5m+7b = 1/10, 4m+7b = 1/12. Subtracting: m = 1/10 - 1/12 = 1/60. So 7b = 1/10 - 5/60 = 1/60, so b = 1/420. Daily wages: 1 man = Rs.140, so 3 men = Rs.420. 4 boys' wages = 4 × (140/60) × (1/7) ≈ Rs.80. Total = Rs.500. Alternatively: wage ratio matches work ratio, so 3m+4b wages = 140×3 + 140×(1/60)/(1/420)×4 = 500.

Multiple choice
  1. 12

  2. 10

  3. 8

  4. 9

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

16 men in 20 days = 320 man-days. 48 women in 16 days = 768 woman-days. So 1 woman = 320/768 = 5/12 man. First 8 days: 12 men + 24 women = 12 + 24×(5/12) = 22 men equivalent = 176 man-days. Remaining: 320 - 176 = 144 man-days for 16 days = 9 men.

Multiple choice
  1. 18 days / 18 दिन

  2. 20 days / 20 दिन

  3. 16 days / 16 दिन

  4. 12 days / 12 दिन

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

A and B work together for 6 days: (1/24 + 1/36)×6 = 5/12 of work done. Remaining 7/12 is done by B and C. B+C's combined rate = 1/36 + 1/48 = 7/144. Time for remaining work = (7/12)÷(7/144) = 12 days. Total time = 6+12 = 18 days.

Multiple choice
  1. $14.5$
  2. $13.33$
  3. $15.6$
  4. $18.8$
  5. None of these.

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

A takes 24 days. B is 20% more efficient, so B takes 24/1.2=20 days. C takes 10 more days than B, so C takes 30 days. Combined rate: 1/20 + 1/30 = 5/60 = 1/12, so together they take 12 days, which is 12×20/18=13.33 days.

Multiple choice
  1. 15 days

  2. 12 days

  3. 18 days

  4. 24 days

  5. None of these

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

Calculate total work: 18 men × 12 hr/day × 20 days = 4320 man-hours. 24 women × 10 hr/day × 15 days = 3600 woman-hours. Equating: 4320 man-hours = 3600 woman-hours, so 1 man-hour = (3600/4320) woman-hours = 5/6 woman-hour. Alternatively: 1 woman-hour = 6/5 man-hours = 1.2 man-hours. Combined daily work in man-hours: (12 × 8) + (15 × 8 × 6/5) = 96 + 144 = 240 man-hours/day. Days needed: 4320 ÷ 240 = 18 days.

Multiple choice
  1. Any two

  2. II and III

  3. I and II

  4. I and III

  5. None of these

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

Let R, S, Su be days for Ranjana, Sanjana, Sushma alone. I: R = S/1.4 and 1/R + 1/S = 1/8. From these, S = 32 days, R = 22.86 days. III: Su = S/0.8 = 40 days. II: 1/R + 1/Su = 11/96. Substituting: 1/22.86 + 1/40 ≈ 0.114 ≈ 11/96. I and III give us all values directly, which also satisfies II. So I and III are sufficient.