How much did ABC Builder charge the customer if the original estimated cost was $450,000 with a mark-up of 18% after a $25,000 cost overrun?

To determine how much ABC Builder charged the customer, we start with the original estimated cost of $450,000. The company incurs a cost overrun of $25,000, which raises the total cost to $475,000 (i.e., $450,000 + $25,000).

Next, we apply the markup percentage to this new total cost. The markup percentage is 18%, so we calculate the markup amount as follows:

[ \text{Markup} = \text{Total Cost} \times \text{Markup Percentage} ]

[ \text{Markup} = $475,000 \times 0.18 = $85,500 ]

Now we add this markup to the adjusted total cost to find the total charge to the customer:

[ \text{Total Charge} = \text{Total Cost} + \text{Markup} ]

[ \text{Total Charge} = $475,000 + $85,500 = $560,500 ]

Therefore, ABC Builder charged the customer $560,500. This calculation reflects the impact of both the initial cost estimate and the cost overrun, as well as the markup applied after accounting for the increased cost.