The Tree-Mendous Math Trick
Alright, a quick “mathematical—but not really” puzzler:
A landscaper comes home and tells his kids, “I planted five rows of four trees each today.”
His kid immediately says, “That’s 20 trees!”
Dad says, “Nope. I only planted 10 trees.”
The kid says, “That’s impossible,”
Dad replies, “No, it isn’t. In fact, you’ve already seen the answer on one of your school papers.”
The kid thinks for a moment… and figures it out.
How can you plant 10 trees in five rows of four, and what did the kid remember that solved it?