NiNAl can alone complete a work in 20 days. Suresh is 25% more efficient than her. He can complete the work in __ days.

Options

A. 14
B. 16
C. 18
D. 20

Answer

To solve the problem, we need to determine how long Suresh will take to complete the work, given that he is 25% more efficient than Neena, who can complete the work in 20 days.

### Step-by-step Solution:

1. **Determine Neena's Work Rate:**
Neena can complete the work in 20 days. Therefore, her work rate (efficiency) is:
\[ \text{Neena's work rate} = \frac{1 \text{ work}}{20 \text{ days}} = \frac{1}{20} \text{ work per day} \]

2. **Calculate Suresh's Work Rate:**
Suresh is 25% more efficient than Neena. To find Suresh's work rate, we first calculate 25% of Neena's work rate:
\[ 25\% \text{ of Neena's work rate} = 0.25 \times \frac{1}{20} = \frac{1}{80} \]
Now, we add this to Neena's work rate to find Suresh's work rate:
\[ \text{Suresh's work rate} = \text{Neena's work rate} + 25\% \text{ of Neena's work rate} = \frac{1}{20} + \frac{1}{80} \]

3. **Finding a Common Denominator:**
To add the fractions, we need a common denominator. The least common multiple of 20 and 80 is 80. Thus, we convert Neena's work rate:
\[ \frac{1}{20} = \frac{4}{80} \]
Now we can add:
\[ \text{Suresh's work rate} = \frac{4}{80} + \frac{1}{80} = \frac{5}{80} = \frac{1}{16} \text{ work per day} \]

4. **Calculate the Time Taken by Suresh:**
Now that we know Suresh's work rate, we can find out how long it will take him to complete the work:
\[ \text{Time taken by Suresh} = \frac{1 \text{ work}}{\text{Suresh's work rate}} = \frac{1}{\frac{1}{16}} = 16 \text{ days} \]

### Final Answer:
Suresh can complete the work in **16 days**.