Total amount paid by the customer for the construction work = $600
Amount spent on the purchase of materials = 3/5 of the total amount = 3/5 * 600 = $360
Remaining amount = $ (600 – 360) = $240
Amount spent on travelling = 1/5 of the remaining amount = 1/5 * 240 = $48
Total amount spent = $ (360 + 48) = $408
Amount left after both the deductions = $ (600 – 408) = $192