Question 646961
If the cost of the ring is $1200, the seller needs to add 50% of this cost to make a profit of 50%. You can calculate this by finding 50% and then adding it to the original cost. 

$1200 * 50% = $600
$1200 + $600 = $1800

You can also multiply a number by 1 + the percentage written as a decimal to increase that number by that percentage.
So: $1200 * 1.50 = $1800.
Or if you wanted to increase it by 25%, multiply the number by 1.25.