###Human: A year ago, the total cost of buying a lawnmower was 2/5 times less than the cost it goes for now. If the cost was $1800 a year ago, calculate how much it would cost Mr. Lucian to buy 4 such lawnmowers., ### Assistant: If the price of a lawnmower was $1800 a year ago, 2/5 less than the cost right now, then it now costs 2/5*1800 = $720 more to buy one lawnmower.
The total cost of buying one lawnmower right now is $1800+$720 = $2520
To purchase 4 such lawnmowers, Mr. Lucian will have to pay $2520*4 = $10080 
 So the answer is :  10080