There are some flowers in a basket and at every next minute they get double. At the 30th minute the basket becomes full. Then at exactly which minute the basket is half filled?

Options

A. 15 minutes
B. 20 minutes
C. 29 minutes
D. 12 minutes

Explanation

To solve the problem step by step, we can follow this reasoning:

1. **Understanding the Doubling Process**: We know that the flowers in the basket double every minute. This means that if we know the number of flowers at any given minute, we can find the number of flowers in the previous minute by halving that number.

2. **Identifying the Full Basket**: According to the problem, the basket becomes full at the 30th minute. Let's denote the number of flowers when the basket is full as F. Therefore, at the 30th minute, the number of flowers is F.

3. **Finding the Number of Flowers at the Previous Minute**: Since the flowers double every minute, we can find the number of flowers in the basket at the 29th minute. To do this, we simply divide the number of flowers at the 30th minute by 2:
\[ \text{Number of flowers at 29th minute} = \frac{F}{2} \]

4. **Conclusion**: Since the basket is half filled at the 29th minute, we conclude that the basket is half filled at the 29th minute.

Thus, the answer to the question is that the basket is half filled at the **29th minute**.