In a school, the bell is rung once after each half an hour. The school starts at 8:00 a.m. and closes at 1:30 p.m. The bell is rung 3 times continuously, at the time of beginning, at the time of lunch break at 10:00 and 10:30 a.m. and at the end. How many times is the bell rung every day?

Options

A. 21
B. 22
C. 19
D. 20

Explanation

To solve the problem step by step, we will calculate the total number of times the bell is rung during the school hours, including the additional times it is rung at specific events.

### Step-by-Step Solution:

1. **Determine the School Hours:**
- The school starts at 8:00 a.m. and closes at 1:30 p.m.
- Total duration of school = 1:30 p.m. - 8:00 a.m.

**Calculation:**
- From 8:00 a.m. to 1:00 p.m. = 5 hours
- From 1:00 p.m. to 1:30 p.m. = 0.5 hours
- Total duration = 5 hours + 0.5 hours = 5.5 hours

**Hint:** Calculate the total time from the start to the end of school to find the duration in hours.

2. **Convert Hours to Half-Hours:**
- Each hour consists of 2 half-hours.
- Therefore, 5.5 hours = 5.5 * 2 = 11 half-hours.

**Hint:** Remember that each hour has two half-hour intervals.

3. **Calculate the Bell Rings During School Hours:**
- The bell rings once after each half-hour.
- Therefore, the bell rings 11 times during the school hours.

**Hint:** For each half-hour interval, count one bell ring.

4. **Add the Special Bell Rings:**
- The bell is rung 3 times at the beginning of school (8:00 a.m.).
- The bell is rung 3 times at the lunch break (10:00 a.m. and 10:30 a.m. are not counted as they are not specified for ringing).
- The bell is rung 3 times at the end of school (1:30 p.m.).

**Calculation:**
- Total special rings = 3 (beginning) + 3 (end) = 6 times.

**Hint:** Identify the specific times when the bell rings more than once and add them to your total.

5. **Calculate the Total Bell Rings:**
- Total bell rings = Bell rings during school hours + Special bell rings
- Total bell rings = 11 + 6 = 17 times.

**Hint:** Combine the regular bell rings with the special occasions to find the final total.

### Final Answer:
The bell is rung a total of **17 times** every day.