General Aptitude

Time & Work Tutorial

Time and work problems are common in aptitude tests. Key: convert work to rate, then add/subtract rates.

Key Formulas

Work, Time & Rate

Open

Basic work-time relationship.

Combined Work (2+ Persons)

Open

Solve when multiple work together.

Pipe & Tank Problems

Open

Inlet-outlet problems (pipes filling/draining).

Work, Time & Rate

Basic work-time relationship.

When to Use: When single person/task duration given.

Step-by-Step Method

  1. Work = Time × Rate (or Efficiency).
  2. Total work = 1 (whole job).
  3. If person completes in T days, rate = 1/T.

Worked Example

Question: A person completes a work in 8 days. In how many days will 2 persons complete?

  1. One person: 8 days to complete 1 work
  2. Rate of 1 person = 1/8 work/day
  3. Rate of 2 persons = 2 × (1/8) = 1/4
  4. Days = 1 ÷ (1/4) = 4 days

Final Answer: 4 days

Option Analysis

Common Mistakes

Quick Shortcut: Time = Work / Rate. More persons = less time proportionally.

Practice This Pattern

Generated 5 focused questions for this pattern.

Q1. Two values are in ratio 5:2. If total is 120, find first value.

  • 82
  • 85
  • 88
  • 91

Answer: 85

Explanation: Step 1: Total parts = 5+2. Step 2: One part = 120/(7). Step 3: First value = 5 parts = 85.

Q2. Two values are in ratio 5:7. If total is 100, find first value.

  • 47
  • 44
  • 38
  • 41

Answer: 41

Explanation: Step 1: Total parts = 5+7. Step 2: One part = 100/(12). Step 3: First value = 5 parts = 41.

Q3. Two values are in ratio 4:6. If total is 120, find first value.

  • 54
  • 48
  • 45
  • 51

Answer: 48

Explanation: Step 1: Total parts = 4+6. Step 2: One part = 120/(10). Step 3: First value = 4 parts = 48.

Q4. Two values are in ratio 7:3. If total is 80, find first value.

  • 59
  • 62
  • 53
  • 56

Answer: 56

Explanation: Step 1: Total parts = 7+3. Step 2: One part = 80/(10). Step 3: First value = 7 parts = 56.

Q5. Two values are in ratio 4:2. If total is 150, find first value.

  • 103
  • 106
  • 100
  • 97

Answer: 100

Explanation: Step 1: Total parts = 4+2. Step 2: One part = 150/(6). Step 3: First value = 4 parts = 100.