Puzzle on Factors and multiples and fractions

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Across
  1. 3. A number that has only two factors
  2. 5. 4 x 5 = 20 : 4 and 5 are the ____ of 20
Down
  1. 1. In 85.369, 85 is a _______ number part
  2. 2. A method used to find LCM of given number
  3. 4. Part of a whole is known as ____.