Barron's Math 2 Question

Test Preparation SAT Subject Test Preparation
1

<p>This is in practice test #2, question 28:
Matrix X has r rows and c columns, and matrix Y has c rows and d columns, where r, c, and d are different. Which of the following statements must be false?
I. The product YX exists
II. The product of XY exists and has r rows and d columns
III. The product XY exists and has c rows and c columns</p>

<p>I thought that II was the only two one, therefore E (I and III) was correct...however the answer in the book says B (II only)..I don't get it</p>

<p>Thanks!</p>

2

<p>“Which of the following statements must be false?”
Did you read the question correctly?</p>

3

<p>Yes, but II isn’t false is it?</p>

4

<p>This one was horrible. I just skipped it hahah too lazy to figure it out</p>

5

<p>II is true. The rest are false. I think it’s a typo.</p>

6

<p>I came across the same question.
It has to be an editing error.</p>