A basketball is inflated in a garage at 25 degrees Celsius to a gauge pressure of 8.0 psi. Gauge pressure is the pressure above atmospheric pressure, which is 14.7 psi. The ball is used on the driveway at a temperature of -7 degrees celsius and feels flat. What is the actual pressure of the air in the ball? What is the gauge pressure?

I'm stuck as to how to start this problem. Any help would be appreciated.

(P1V1)/T1=(P2V2)/T2
Don't forget to change Celsius to Kelvin.