Shatabdi Express has a capacity of 500 seats of which 10% are in Executive class and the rest being Chair cars. During one journey, the train was booked 85% of its capacity. If Executive class was booked to 96% of its capacity, then how many chair car seats were empty during that journey?

Answer

To solve the problem step by step, we will break down the information provided and calculate the required values.

### Step 1: Determine the number of Executive Class and Chair Car seats.
- Total seats in the Shatabdi Express = 500
- Percentage of Executive Class seats = 10%
- Therefore, the number of Executive Class seats (E) = 10% of 500
\[ E = \frac{10}{100} \times 500 = 50 \]
- The rest are Chair Car seats.
- Percentage of Chair Car seats = 100% - 10% = 90%
- Therefore, the number of Chair Car seats (C) = 90% of 500
\[ C = \frac{90}{100} \times 500 = 450 \]

### Step 2: Calculate the total number of seats booked during the journey.
- The train was booked to 85% of its capacity.
- Total seats booked = 85% of 500
\[ \text{Total booked} = \frac{85}{100} \times 500 = 425 \]

### Step 3: Calculate the number of Executive Class seats booked.
- The Executive Class was booked to 96% of its capacity.
- Therefore, the number of Executive Class seats booked = 96% of 50
\[ \text{Executive Class booked} = \frac{96}{100} \times 50 = 48 \]

### Step 4: Calculate the number of Chair Car seats booked.
- Total seats booked = Executive Class booked + Chair Car booked
- Let the number of Chair Car seats booked be \( x \).
\[ 425 = 48 + x \]
- Solving for \( x \):
\[ x = 425 - 48 = 377 \]

### Step 5: Calculate the percentage of Chair Car seats booked.
- The total number of Chair Car seats is 450.
- Therefore, the percentage of Chair Car seats booked =
\[ \frac{377}{450} \times 100 \]
\[ \text{Percentage booked} = \frac{377 \times 100}{450} \approx 83.78\% \]

### Step 6: Calculate the number of empty Chair Car seats.
- The percentage of empty Chair Car seats = 100% - 83.78%
\[ \text{Empty percentage} = 100 - 83.78 = 16.22\% \]
- Therefore, the number of empty Chair Car seats = 16.22% of 450
\[ \text{Empty seats} = \frac{16.22}{100} \times 450 = 72.99 \approx 73 \]

### Final Answer:
The number of Chair Car seats that were empty during that journey is approximately **73**.

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