what size is the tube and the tire?

reason Im asking is the shop I was using was putting tubes in that were too big (according to a lot on here). The tire is 26X1.50 and the tubes they were using were maybe 1.50-2.5 (approximate)

was getting mucho flats near the valve stem. most on here will say use tubes that are on the smaller side, like maybe 1.0-1.50