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In three colored urns - white, black and yellow, total 108 balls are placed. There are twice as many balls in the black and white urns combined as there are in the yellow urn and twice as many in the yellow urn as there are in the white urn. How many balls are there in the black urn?

In three colored urns - white, black and yellow, total 108 balls are placed. There are twice as many balls in the black and white urns combined as there are in the yellow urn and twice as many in the yellow urn as there are in the white urn. How many balls are there in the black urn? Correct Answer 54

Let the number of white urns balls be x.

Yellow urns = 2 × white urn = 2x

(Black + White) urn = 2 × Yellow urn = 4 x

White + Black + Yellow = 108

4x + 2x = 108

6x = 108

x = 18

Thus, the number of Black urns balls = 3x = 18 × 3 = 54.

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