A common denominator is 72.
The least common denominator (LCD) is 1.
The least common denominator is 2 * * * * * That is totally wrong. LCD(24, 36) = 72
A common denominator, though not the least, is 240.
A common denominator, though not the least, is 1680.
It is: 24
A common denominator, though not the least one, is 24*21 = 504.
A common denominator, though not the least one, is 16*24 = 384.
A common denominator, though not the least, is 12960.
The common denominator is usually the Lowest (or Least) Common Multiple of the numbers involved. Where two numbers have no common factors then the LCM is simply the product of those numbers. As 19 is a prime number and has no factors in common with 18 then the common denominator is 18 x 19 = 342.
264
360