If white balls have a mass of 5.0 grams and black balls have a mass of 2.0 grams, in a box containing white and black balls with 2/3 of the balls being white, what is the average mass of a single ball in this box?

1 Answer
Sep 2, 2015

Average mass (per ball) = 4.0 g.

Explanation:

If 2/3 of the balls are white

then we could group the balls into groups of 3 with 2 white balls and 1 black ball in each group.

Each group would weight 2xx5.0" g" + 1xx2.0 " g "= 12.0 " g"

and since there are 3 balls in each group,
the average weight would be (12.0" g")/3 = 4.0 " g"