Question

there are 22 blue and black balls in the a basket in the ratio blue balls : black balls is 7:4. 4 more black balls are added.find the percentage of blue balls in the group.find the percentage increase in black balls.

Answer 1

There are 14 Blue balls, and 8 Black balls to begin with. Meaning  36.36% black balls. After the 4 more balls are added, there are 14 Blue and 12 Black balls. Now there is a 46.15% of Black balls. Meaning the increase is 0.3636x = 46.15, meaning x= 1.2692. This means the increase in Black balls is 126.92%. The percentage of Blue balls is 53.85%. All percentages are to 2d.p.