What is least common multiple of 28,12,14,21?

There are 20 children in the cast of a class play and 8 of the children are boys of the boys 4 have a speaking part in the play and of the girls 8 do not have a speaking part in the play if a child from the cast of the place chosen at random what is the probability that the child has a speaking part

Ateacher noticed 5/8 of the students were wearing either blue shorts or white shorts. write two different ways this could be done.

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