Hi Matthew.
If 5 meters of rope costs $18.00, then that means 1 meter of rope costs $3.60.
We determine this cost by dividing 18 by 5.
Now, we need to set to scale how many meters are in 250 centimeters. To solve for this, we need to divide 250 by 100, as 100 centimeters is equivalent to 1 meter.
250 / 100 = 2.5.
As we can see, Kim bought 2.50 meters of rope, and as each meter costs $3.60, we need to multiply 2.50 by 3.60 to determine the total cost of Kim's purchase.
2.50 * 3.60 = 9.00
Kim spent $9.00 on rope.
I hope this helps!