Melissa uses bags of mulch that weigh 40 pounds each. she needs to carry 10 bags to her truck. she usually carries one bag at a time. would she do less work if she carried two bags at a time?

Work done = force applied in the direction of motion × distance 
in this case, the force applied by melissa is not in the direction of motion of object, therefore work done is only dependent on and directly proportional to the distance the object moves. since the distance for one bag or two bag remains the same, workdone also stays the same.