Assume you have a computer that contains 1GB of memory. It contains four memory slots. Each slot can contain 128 MB, 256 MB, 512MB, 1 GB, or 2GB memory modules. two of the slots contains a 512MB memory module. What memory chip would you buy to increse the memory on the computer to 4 gb? what is the maximum memory on the computer?

To increase the memory on the computer to 4GB, you need to calculate the total memory already installed and then determine the required memory chip size.

Here are the steps to follow:

1. Calculate the total memory already installed in the computer:
- Two slots contain a 512MB memory module each.
- Multiply the memory module size (512MB) by the number of slots (2).
- Total memory already installed = 512MB * 2 = 1024MB = 1GB.

2. Determine the required memory chip size to increase the memory to 4GB:
- The computer already has 1GB of memory.
- To reach 4GB, you need to add 3GB more.
- Convert 3GB to MB: 1GB = 1024MB, so 3GB = 3 * 1024 = 3072MB.

3. Choose the appropriate memory chip size that will allow you to reach 4GB:
- Among the available memory chip sizes: 128 MB, 256 MB, 512MB, 1GB, and 2GB.
- Find the memory chip size that is closest to the required 3072MB but doesn't exceed it.
- The closest memory chip size is 2GB (2048MB).

Therefore, to increase the memory on the computer to 4GB, you would buy a 2GB memory chip.

To determine the maximum memory the computer can have, you need to consider the maximum capacity of each memory slot.

Here are the steps to determine the maximum memory:

1. Find the largest memory module size available among the memory slots:
- The available memory module sizes are 128 MB, 256 MB, 512MB, 1GB, and 2GB.

2. Add the maximum memory module sizes of each slot:
- Since the computer has four slots, identify the maximum capacity for each slot.
- Slot 1: Maximum capacity = 2GB
- Slot 2: Maximum capacity = 2GB
- Slot 3: Maximum capacity = 2GB
- Slot 4: Maximum capacity = 2GB

3. Sum up the maximum capacities of all slots:
- Total maximum memory = Maximum capacity of Slot 1 + Slot 2 + Slot 3 + Slot 4 = 2GB + 2GB + 2GB + 2GB = 8GB

Therefore, the maximum memory that can be installed on the computer is 8GB.

To increase the memory on the computer to 4GB, you need 3.5GB more memory since the computer already has 0.5GB (two 512MB modules).

Since each memory slot can contain different memory module sizes, you need to select the appropriate memory chip(s) that will fit the remaining slots while adding up to 3.5GB.

Let's break down the available memory module options:

- 128MB
- 256MB
- 512MB (two slots already occupied)
- 1GB
- 2GB

To add the remaining 3.5GB of memory, you can use two 2GB memory chips and one 512MB memory chip. This configuration fills up the remaining slots.

So, you would buy two 2GB memory chips and one 512MB memory chip.

As for the maximum memory on the computer, since there are four memory slots and each slot can contain a maximum of 2GB, the total maximum memory the computer can hold is 8GB (4 slots * 2GB per slot).