Q: I am unable to install any apps cos my iPad need update iOS 7 pls tell me how can I update My version pls

HI my name is sameeralam I am using iPad old model no. Is MB294ZP version 5.1.1(9b206)

SN.no GB033QCEZ3A I am unabletoinstall any apps cos iPad need update iOS 7pls tell me how can I install any apps without update version pls replymeas soon as possible

THanks Apple Team