A wholesaler buys plastic lamps for $18 each and sells them for $30.60. What is the percent markup based on cost

(30.60-18)/18 = ?

70%

To find the percent markup based on cost, we need to calculate the price difference between the selling price and the cost price, and then express it as a percentage of the cost price.

The cost price of the plastic lamp is $18, and the selling price is $30.60. Therefore, the markup is $30.60 - $18 = $12.60.

To calculate the markup as a percentage of the cost price, you divide the markup by the cost price and multiply by 100:

Markup percentage = (Markup / Cost price) * 100

In this case, the markup is $12.60, and the cost price is $18. Thus:

Markup percentage = ($12.60 / $18) * 100 = 0.7 * 100 = 70

Therefore, the percent markup based on cost is 70%.