I am struggling in Gear ratio assaining to my Spur gear model

I can not run my spur gear bcoz of the gear ratio putting in the Assembly mate, CAN ANY ONE HELP ME on this?

My gear details

Spur Pinion - 18T / OD 50mm

Spur Gear - 24T / OD 65mm

Nagu.S

SolidworksAssemblies