Question
PSLE
A box contained red balls and green balls. 40% of the balls were green. After some black balls were added to the box, 22% of the balls were green. What percentage of the balls in the box were black?
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PSLE
A box contained red balls and green balls. 40% of the balls were green. After some black balls were added to the box, 22% of the balls were green. What percentage of the balls in the box were black?