Using Statement-I alone: This gives us the size of the software but does not provide any information about the transfer rate, which is necessary to calculate the download time. Hence, this statement alone is not sufficient.

Using Statement-II alone: This tells us the transfer rate but does not provide the size of the software. Without knowing the size, we cannot calculate the time required to download. Hence, this statement alone is not sufficient.

Combining Statement-I and Statement-II: From Statement-I, we know the software size is 12 megabytes. From Statement-II, we know the transfer rate is 2.4 kilobytes per second. We can calculate the time required to download the software using the formula:

• Download Time = Size of the Software / Transfer Rate

We need to convert the size to the same unit as the transfer rate:

• 1 megabyte = 1024 kilobytes, so 12 megabytes = $12 \times 1024 = 12288$ kilobytes.

Now, calculate the time:

• Time = $12288$ kilobytes / $2.4$ kilobytes per second = $5120$ seconds.

Thus, combining both statements gives us the unique solution for the download time.

Conclusion: The question can be answered by using both statements together, but cannot be answered using either statement alone.