Can I put 3#10 and 3#14 wires with a ground in a 3/4" conduit? The conduit is underground between two buildings, is this okay?

What kind of conduit?

And what type of insulation on the wires?

And why so many conductors?
Are you aware that you can only have one circuit maximum at a detached structure? After that you need a feeder and sub-panel.

I asked about the 3#10 and 3#14 wires in a 3/4" conduit. The details are as follows: the conduit is grey plastic pipe, the insulation is thwn on the wires, the #10 wires will feed a sub panel from a 30 amp breaker in the main panel, the sub panel will have its own grounding rod and separated ground from the neutral. The #14 wires are for an outside lighting fixture that will be controlled by 3way switches, one in the house and one in the garage. The pipe is about 35 feet long and is buried 4 feet deep in the ground. There will also be a bare copper ground wire along with the insulated conductors in the pipe. The question is, is this okay to do? Thanks for your time and expertise.

3/4" is fine for this, although I would have gone to 1" myself.

I would use an insulated #10 for ground, stranded on all?