What is the last question asked in the book of Revelation?

Answer 1

The last time in the book of Revelation that uses a question mark (indicating a question) is in Revelation 17:7 KJV (King James Version):

"And the angel said unto me, Wherefore didst thou marvel? I will tell thee the mystery of the woman, and of the beast that carrieth her, which hath the seven heads and ten horns."

But as indicated by others, there is also kind of a question in Revelation 18:18. In the KJV it doesn't have a question mark associated with it, but is it phrased as a question:

"And cried when they saw the smoke of her burning, saying, What city is like unto this great city!"

Answer 2

The Book of Revelation is as its title suggests - God's revelation to mankind of the things that have and must still come. As such, questions are not dominant. Here is a rhetorical one that appears last:

Revelation 18:18 New King James Version (NKJV):
18 and cried out when they saw the smoke of her burning, saying, "What is like this great city?"

Answer 3

KJV Revelation 22:21 "The grace of our Lord Jesus Christ be with you all. Amen."

Answer 4

The grace of the Lord Jesus be with all the saints. Amen.

Revelation 22:21 NRSV

Answer 5

Amen is the last verse in The Bible