Question:medium

A man completes \( \frac{5}{8} \) part of a job in 10 days. At this rate, how many more days will he take to complete the job?

Show Hint

Pay close attention to the wording. The question asks for "how many more days," not the "total number of days." This is a common trap in competitive exams.
Updated On: Feb 19, 2026
  • 5
  • 6
  • 7
  • 8
Show Solution

The Correct Option is B

Solution and Explanation

Step 1: Concept Introduction:
This is a work and time problem. The objective is to determine the total time for the job and then the remaining time.
Step 2: Fundamental Principle:
Given a portion of work completed within a specific timeframe, we can ascertain the time required for the outstanding portion.
Step 3: Detailed Analysis:
Method 1: Calculate Total Time First
\( \frac{5}{8} \) of the job is completed in 10 days.
To calculate the time for the entire job (1 unit of work), we apply the formula:
\[ \text{Total time} = \frac{\text{Duration}}{\text{Fraction of work}} = \frac{10 \text{ days}}{\frac{5}{8}} = 10 \times \frac{8}{5} = 16 \text{ days} \]The total duration for the job is 16 days.
Time already spent is 10 days.
\[ \text{Remaining time} = \text{Total time} - \text{Time spent} = 16 - 10 = 6 \text{ days} \]Method 2: Calculate Remaining Work Directly
Fraction of work completed = \( \frac{5}{8} \)
Fraction of work remaining = \( 1 - \frac{5}{8} = \frac{3}{8} \)
It is known that \( \frac{5}{8} \) of the work takes 10 days.
We calculate the time for \( \frac{1}{8} \) of the work:
\[ \text{Time per } \frac{1}{8} \text{ work} = \frac{10 \text{ days}}{5} = 2 \text{ days} \]Subsequently, we calculate the time for the remaining \( \frac{3}{8} \) of the work:
\[ \text{Time for } \frac{3}{8} \text{ work} = 3 \times (\text{Time per } \frac{1}{8} \text{ work}) = 3 \times 2 = 6 \text{ days} \]Step 4: Conclusion:
The remaining duration to complete the job is 6 days.
Was this answer helpful?
1