Solution

To calculate the total hard disk space required, let's break it down:

1. Black and white images:

• Each image is 1-megapixel.
• Black and white images use 1 bit per pixel (since only two colors: black or white).
• 1 megabyte (MB) is 1,048,576 bytes, and 1 byte is 8 bits.

So for each black-and-white image:

• 1-megapixel = 1,000,000 pixels.
• Each pixel requires 1 bit, so each image uses 1,000,000 bits.
• Converting bits to bytes: \(\frac{1,000,000}{8}\) = 125,000 bytes = 125 KB.

For 8 black-and-white images:

• 125 KB × 8 = 1,000 KB = 1 MB.

2. 8-color image:

• The image is 8-megapixel.
• 8 colors means 3 bits per pixel (since 2^3 = 8).
• 8 megapixels = 8,000,000 pixels.

So for the 8-color image:

• 8 megapixels × 3 bits per pixel = 24,000,000 bits.
• Converting bits to bytes: \(\frac{24,000,000}{8}\) = 3,000,000 bytes = 3 MB.

Total hard disk space:

• Space for 8 black-and-white images: 1 MB.
• Space for one 8-color image: 3 MB.

Total = 1 MB + 3 MB = 4 MB.

Therefore, the correct answer is: 2) 4 MB.