what value will the MEMORY_MAX_TARGET parameter be set by default?

Examine the exhibit to view the parameters set in your parameter file. (Click the Exhibit(s) button.)
You restart the instance.
To what value will the MEMORY_MAX_TARGET parameter be set by default?

A.
120M

B.
320M

C.
480M

D.
600M

Explanation:
The MEMORY_MAX_TARGET parameter will be set to 600M by default. Oracle 11g has two new Automatic Memory Management initialization parameters, namely MEMORY_TARGET and MEMORY_MAX_TARGET. MEMORY_TARGET represents the total amount of memory that can be allocated to SGA and PGA memory structures. If the SGA_TARGET and PGA_AGGREGATE_TARGET parameters are specified and MEMORY_TARGET is set to a value greater than zero, they represent the minimum sizes of the SGA and PGA. MEMORY_TARGET should be no less than the sum of SGA_TARGET and PGA_AGGREGATE_TARGET.

If not explicitly specified, MEMORY_TARGET defaults to 0. The MEMORY_MAX_TARGET parameter represents the largest possible value to which MEMORY_TARGET can be set. The MEMORY_MAX_TARGET parameter can be manually set, or it will be derived. If you specify a nonzero value for MEMORY_TARGET and do not set MEMORY_MAX_TARGET, MEMORY_MAX_TARGET will be set to the same value as MEMORY_TARGET by default, which is 600M in this scenario. MEMORY_MAX_TARGET is set to 0 if MEMORY_TARGET is not set or is explicitly set to 0.

All of the other options are incorrect because if MEMORY_TARGET is set to a nonzero value and MEMORY_MAX_TARGET is not set, MEMORY_MAX_TARGET will default to the same value as MEMORY_TARGET, which in this scenario is 600M.

SYBEX Oracle 1Z0-053 Study Guide, Chapter 11: Managing Database Resources
If you don’t set MEMORY_MAX_TARGET, it will default to the value of MEMORY_TARGET.

Oracle Press 1Z0-053 Study Guide, Chapter 11: Managing Database Resources
The exam very specifically gives you scenarios combining various initialization parameters such as MEMORY_TARGET and SGA_TARGET set to zero and nonzero values, and then asks you what the effect is on instance memory and other initialization parameters. You’ll have to memorize the contents of following Tables 10-1 and 10-2 to answer those questions!