Human: To run his grocery store, Mr. Haj needs $4000 a day. This money is used to pay for orders done, delivery costs and employees' salaries. If he spends 2/5 of the total operation costs on employees' salary and 1/4 of the remaining amount on delivery costs, how much money does he pay for the orders done? Assistant:
The total amount of money Mr. Haj used to pay for employee salary is 2/5*$4000 = $1600
After paying the employee salaries, Mr. Haj remains with $4000-$1600 = $2400
He also uses 1/4*$2400= $600 on delivery costs.
The remaining amount of money that he uses to pay for orders is $2400-$600 = $1800