Work Efficiency
SSC GD Exam Preparation - Quantitative Aptitude
1️⃣ Basic Concepts
Work
Anything that takes time to complete.
Time
How long it takes to finish the work.
Efficiency
Amount of work done in 1 day.
2️⃣ Key Formulae
🔹 Formula 1: Work = Time × Efficiency
This is the fundamental relationship between work, time, and efficiency.
🔹 Formula 2: Efficiency = Work / Time
Efficiency is calculated as work divided by time taken.
🔹 Formula 3: If A completes work in 'x' days
A's 1-day work = 1/x
Time ∝ 1/Efficiency
🔹 Formula 4: If A and B work together
Combined 1-day work = A's 1-day work + B's 1-day work
🔹 Formula 5: Efficiency Ratio ↔ Time Ratio
If efficiency ratio = a : b, Then time ratio = b : a
3️⃣ Important Points
Higher efficiency → Less time needed
Lower efficiency → More time needed
If a person becomes x% more efficient → Time decreases
If efficiency decreases → Time increases
🧠 Practice Section: 15 Practice Questions (With Answers)
Test your time & work efficiency concepts with these SSC GD level practice questions. Click on "View Answer" to check your understanding.
Q1. A can finish a work in 10 days. What is his 1-day work?
View Answer
1/10
Q2. B can complete a work in 20 days. What is his efficiency ratio compared to A who works in 10 days?
View Answer
A : B efficiency = 20 : 10 = 2 : 1
Q3. A takes 12 days, B takes 6 days. Who is more efficient and by what ratio?
View Answer
Efficiency ratio = 6 : 12 = 1 : 2, So B is twice as efficient as A.
Q4. A's efficiency is 25% more than B. If B finishes work in 20 days, find A's time.
View Answer
A's efficiency = 125% of B = 5/4, Time ratio = 4 : 5, A's time = 20 × (4/5) = 16 days
Q5. A and B can do a job in 12 days and 15 days respectively. How long if both work together?
View Answer
Their 1-day work = 1/12 + 1/15 = 9/60 = 3/20, Total time = 20/3 = 6.67 days
Q6. A can finish a piece of work in 8 days. B is 50% as efficient as A. Find B's time.
View Answer
Efficiency ratio = 100 : 50 = 2 : 1, So B's time = 8 × 2 = 16 days
Q7. A is twice as efficient as B. Together they finish work in 12 days. Find individual times.
View Answer
Efficiency A : B = 2 : 1, Total parts = 3, Total work = 12, A's days = 12/2 = 6 days, B's days = 12/1 = 12 days
Q8. A can do a work in 15 days. After 5 days A leaves. Remaining work is done by B in 10 days. Find B's time.
View Answer
A's 5-day work = 5/15 = 1/3, Remaining work = 2/3, B's 1-day work = (2/3)/10 = 1/15, So B's time = 15 days
Q9. A alone can do work in 18 days, B in 24 days. How much work do they finish together in 1 day?
View Answer
1-day work = 1/18 + 1/24 = (4+3)/72 = 7/72 part
Q10. If A's time is 25% less than B, how much more efficient is A?
View Answer
Time ratio = 75 : 100 = 3 : 4, Efficiency ratio = 4 : 3, So A is 33.33% more efficient
Q11. A and B together finish a job in 8 days. A alone can do it in 12 days. Find B's time.
View Answer
1-day(A + B) = 1/8, 1-day(A) = 1/12, 1-day(B) = 1/8 – 1/12 = 1/24, So B's time = 24 days
Q12. A does 2/5 of work in 4 days. In how many days will he finish the full work?
View Answer
If 2/5 work → 4 days, Full work → 4 × (5/2) = 10 days
Q13. A and B's efficiencies are in ratio 3 : 2. If B takes 30 days, find A's time.
View Answer
Time ratio = 2 : 3, A's time = 30 × (2/3) = 20 days
Q14. A is 20% more efficient than B. Together they finish work in 15 days. Find B's time.
View Answer
Efficiency A : B = 120 : 100 = 6 : 5, Total = 11 parts, Total work = 11 × 15 = 165, B's time = 165/5 = 33 days
Q15. A can finish a work in 30 days working alone. B is 50% more efficient. Find time together.
View Answer
B's efficiency = 150% of A = 3/2, A's 1-day work = 1/30, B's 1-day work = 3/2 × 1/30 = 1/20, Together = 1/30 + 1/20 = 1/12, Time = 12 days
✅ SSC GD Exam Strategy
🟢 Remember efficiency is inversely proportional to time
🟢 Practice 1-day work calculations for quick solutions
🟢 Master efficiency ratio to time ratio conversions
🟢 Learn to handle percentage efficiency changes
🟢 Time yourself - aim for 45-60 seconds per time & work question
You've completed Time & Work Efficiency Concepts!
SSC GD Tip: Time & Work problems are very common in the quantitative section. Focus on understanding the inverse relationship between efficiency and time. Remember that 1-day work calculations are key to solving most problems quickly. Practice efficiency ratios and percentage changes as they frequently appear in exams. Regular practice with previous year SSC GD questions will build your speed and accuracy in solving time & work problems efficiently.
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