It is: 140
20 and 14 are both integers. The common denominator of 20/1 and 14/1 is 1. The least common multiple is 140.
A common denominator, though not the least one, is 200.
A common denominator of 20 and 30 is 600. This is NOT the least common denominator, though.
the common denominator for 9/8 and 7/20 is 40. (45/40 and 14/40)
A common denominator, though not the least one, is 14*49 = 686.
The common denominator is 28.
A common denominator, though not the least, is 168.
The greatest common denominator is infinite.
A common denominator, though not the least one, is 14*12 = 168.
A common denominator, though not the least one, is 12*20 = 240.
A common denominator, though the least, is 260.
20