Answer :

Factors of 144:
1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 36, 48, 72, 144

Factors of 96:
1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96

The common factors of both numbers:
1, 2, 3, 4, 6, 8, 12, 16, 24, 48

GCF = 48