To calculate the price of the globe after the 20% mark-up, we need to add 20% of the original price to the original price.
20% of $31 is (20/100) * $31 = $6.20.
Adding the mark-up to the original price:
$31 + $6.20 = $37.20.
Therefore, the price of the globe after the mark-up is $37.20.