it's so weird to see the bike where the image has been flipped or mirrored. The drive side with the chain should be on the side facing the camera with the bike in that position.

That said, the image is pretty low resolution. Judging from what I can see I would guess early to mid 80's. I recall finding a reference to Apollo serial numbers, but can't recall exactly where. Knowing details of the various bike components would offer a better estimate. Is this your bike that you're selling? Or wanting to buy?