Level 3
10 days ago, Ruth had a total of 250 green and violet stickers. 40% of her stickers were violet stickers. Today, her father gave her some more stickers. As a result, her green stickers increased by 30%. Now, 50% of her stickers are violet stickers. How many violet stickers did her father give her?
Level 3
There was an equal number of mangoes and pineapples. On Monday, some mangoes were added, such that the number of mangoes increased by 80%. On Tuesday, the number of mangoes further increased by 50% and the number of pineapples decreased by 20%. There were 38 more mangoes than pineapples in the end. How many mangoes and pineapples were there altogether at first?
Level 3
At first, the ratio of the number of boys to the number of girls at a school playground was 2 : 5. When 48 girls and some boys entered the playground, the number of girls increased by 12% and the total number of children at the playground increased by 20%.
How many boys were there at first?
What percentage of the children at the playground were boys in the end? Express your answer as a mixed number.
