QUES: He did go to the Observatory but decided that he would prefer not to accept the post there but rather remain at Cambridge

correct the punctuation.

CORRECTED: He did go to the Observatory but decided that he would prefer not to accept the post there, but rather remain at Cambridge.

QUES: 29km from Dublin Centre

correct the punctuation.

CORRECTED: 2.9km from Dublin Centre

QUES: Mac volumes refuse to mount While using external hard drive on Mac computer sometimes data may be lost or become unreadable when partitions fail to mount

correct the punctuation.

CORRECTED:
Mac volumes refuse to mount: While using external hard drive on Mac computer, sometimes data may be lost or become unreadable when partitions fail to mount.