The question had to do with how many buckets of material would fit in a truck. The correct answer is as many as will fit. The skill of the operator, the type of dirt, the moisture in the dirt, the reach of the bucket into the bed of the truck, the power of the hoist to dump the bed, is there room to load from both sides or only from the rear all need to be answered to give a good answer and that info is not given.
The best you can do is count the first load and watch the springs as you load the truck so you know when to stop. Besides each and every scoop will not be a full bucket so the number of buckets may change on every load.
2.5 x 27 / 10 = 6.7 buckets
2.5 x 27 /13 = 5.2 buckets
3 x 27/ 10 = 8.1 buckets
3 x 29 / 13 = 6.7 buckets
So you get 5 to 8 buckets per truckload.
Does this work in the real world? Maybe.
The best you can do is count the first load and watch the springs as you load the truck so you know when to stop. Besides each and every scoop will not be a full bucket so the number of buckets may change on every load.
2.5 x 27 / 10 = 6.7 buckets
2.5 x 27 /13 = 5.2 buckets
3 x 27/ 10 = 8.1 buckets
3 x 29 / 13 = 6.7 buckets
So you get 5 to 8 buckets per truckload.
Does this work in the real world? Maybe.