bfchat.brainformation.com

This is from an article I found about viral memes. The claim is that a lot of people are getting confused and can't come up with an answer. I solved it (correctly it seems) in about 7.3 seconds. Do you find this problem simple too, or are you among the confused ones?

Unless I'm missing something here. He had to start off with $60.00 in order to buy the horse for $60.00
Either way, he's still Down $60.00 in the first transaction. So...
-60
+70
=10
-80
=-70
+90
=20
He's ahead by $20.00
Even if you start off with him having $60.00
60
-60
=0
+70
=70
-80
=-10
+90
=80
He started with $60.00, he now has $80.00, so his profit is $20.00
If this is not correct, what am I missing?

You are correct. Here is how I reasoned:

Purchases: $60 + $80 = $140
Sales: $70 + $90 = $160

Sales - Purchases = Profit/Loss
$160 - $140 = $20 Profit

i love those math problems people lose their minds over!

Hah! I had the same reasoning believe it or not with this test