Question
PSLE
A box contained black balls and red balls. 60% of the balls were red. After some blue balls were added to the box, 15% of the balls were red. What percentage of the balls in the box were blue?
2 m

Click button first when a symbol is required. X

PSLE
A box contained black balls and red balls. 60% of the balls were red. After some blue balls were added to the box, 15% of the balls were red. What percentage of the balls in the box were blue?