What is the minimum amount of memory (in bytes) that is sufficient to store a 32 x 32 pixel black

What is the minimum amount of memory (in bytes) that is sufficient to store a 32 x 32 pixel black and white bitmap if the image is known to use no more than 16 shades of gray?

A 16-color dot occupies 4 bits in memory.

An image with a resolution of 32×32 contains 1024 pixels.

To find the amount of memory that the image will occupy, you need to multiply the total number of pixels by the amount of memory occupied by one pixel:

1024 * 4 = 4096 bits = 512 bytes