“How many apples grow on a tree?/“All of them.”

“How many apples grow on a tree?” is a popular children’s riddle. “All of them” is the answer. The joke has been cited in print since at least 1976.
 
“How many cranberries grow on a bush?” is a similar joke that has been cited in print since at least 2008. Related jokes include “How many stars are in the sky?”/“All of them” (cited in print since at least 1987) and “How many bones are in a human body?”/“Usually, all of them” (cited in print since at least 2016).
 
   
Newspapers.com
21 November 1976, The Robesonian (Lumberton, NC), The Mini Page by Betty Debnam, pg. 3, col. 1:
Q. How many apples grow on a tree?
A. All of them.
Frances Adams, age 7, Lumberton
 
Google Books
The Zaniest Riddle Book in the World
By Joseph Rosenbloom
New York, NY: Sterling Publishing Company, Inc.
1984
Pg. 52:
How many apples grow on a tree?
All of them.
 
26 April 1999, Indiana (PA) Gazette, “Mighty Funny’s Mini Jokes,” The Mini Page by Betty Debnam, pg. 4, col. 2:
Q: How many lemons grow on a tree?
A: All of them.
(all jokes sent in by Anelia Knight)
 
Twitter
Ryan Kiley
‏@ryan_kiley
Q: “How many apples grow on a tree”
A: “All of them”
#WorstPopsicleStickJokesEver
9:23 AM - 20 Oct 2011
 
Twitter
Miss Universe
‏@TheAfricanFish
On a serious note, who the fuck writes the Popsicle stick jokes? “How many apples grow on a tree? All of them.”
LIKE ARE YOU KIDDING ME.
9:19 PM - 28 Aug 2014