You are right that N=32 does satisfy the condition that N is less than 40, however if N=32, we do not satisfy the condition given in statement 2, which says that N is equal to four less than four times the unit digit. I was referring to the condition given in the statement.

I am actually going to redo this video and incorporate another approach.

SO says

At 2.14 mark, you said that N = 4* 9 -4 = 32 doesn’t satisfy the condition but 32 is less than 40. Did 9 satisfy the condition as well as 8,7,6?

GMAT Quantum says

You are right that N=32 does satisfy the condition that N is less than 40, however if N=32, we do not satisfy the condition given in statement 2, which says that N is equal to four less than four times the unit digit. I was referring to the condition given in the statement.

I am actually going to redo this video and incorporate another approach.

GMAT Quantum says

I updated the video with a different explanation.