There isn't a "standard" dump truck.. they could be anything from a 1 ton pickup up to 70+ ton off-highway vehicles. For a Class 7 or Class 8 truck for vocational work, most will use a 10 lug setup.
Jack it up and remove the lug nuts.
A 1999 Chevy 1500 truck typically has five lug nuts per wheel. Therefore, with four wheels, the total number of lug nuts is 20. This configuration is standard for most light-duty trucks from that era.
5 lug nuts on
There are 6 on standard suburban
Five
5
5
5
15
5
5
5 is average.