A can do 20% of a job in 7 days and B can do 25% of the job in 7 days if they worked alone. How much of the job (in percentage) can they complete in 7 days if they worked together? 

This question was previously asked in
SSC CGL 2023 Tier-I Official Paper (Held On: 17 Jul 2023 Shift 4)
View all SSC CGL Papers >
  1. 38%
  2. 52%
  3. 56%
  4. 45%

Answer (Detailed Solution Below)

Option 4 : 45%
vigyan-express
Free
PYST 1: SSC CGL - General Awareness (Held On : 20 April 2022 Shift 2)
3.6 Lakh Users
25 Questions 50 Marks 10 Mins

Detailed Solution

Download Solution PDF

Given:

A can do 20% of a job = 7 days

B can do 25% of the job = 7 days

Formula used:

Total work = efficiency × time

Calculation:

A can do 20% of a job = 7 days

A can do 100% of a job = 7 × 5 = 35 days

B can do 25% of the job = 7 days

B can do 100% of the job = 7 × 4 = 28 days

According to the question:

⇒ A × 35 = B × 28

⇒ A/B = 4/5

Total work = A × 35 = 4 × 35 = 140 units

Both work together for 7 days = (5 + 4) × 7

⇒ 9 × 7 = 63 units

Percentage job complete in 7 days = (63 × 100)/140

⇒ 9 × 5 = 45%

∴ The correct answer is 45%.

Latest SSC CGL Updates

Last updated on Jun 13, 2025

-> The SSC CGL Notification 2025 has been released on 9th June 2025 on the official website at ssc.gov.in.

-> The SSC CGL exam registration process is now open and will continue till 4th July 2025, so candidates must fill out the SSC CGL Application Form 2025 before the deadline.

-> This year, the Staff Selection Commission (SSC) has announced approximately 14,582 vacancies for various Group B and C posts across government departments.

->  The SSC CGL Tier 1 exam is scheduled to take place from 13th to 30th August 2025.

->  Aspirants should visit ssc.gov.in 2025 regularly for updates and ensure timely submission of the CGL exam form.

-> Candidates can refer to the CGL syllabus for a better understanding of the exam structure and pattern.

-> The CGL Eligibility is a bachelor’s degree in any discipline.

-> Candidates selected through the SSC CGL exam will receive an attractive salary. Learn more about the SSC CGL Salary Structure.

-> Attempt SSC CGL Free English Mock Test and SSC CGL Current Affairs Mock Test.

-> Candidates should also use the SSC CGL previous year papers for a good revision. 

More Work Efficiency Questions

More Time and Work Questions

Get Free Access Now
Hot Links: teen patti gold apk all teen patti game teen patti king