Level 3
There were some pink erasers and blue erasers. The erasers were packed into 2 bags. At first, Bag A contained 480 erasers and 40% of them were blue erasers. Bag B contained 300 erasers and 80% of them were blue erasers. How many pink erasers and blue erasers in total must be moved from Bag A to Bag B such that 20% of the erasers in Bag A are pink and 50% of the erasers in Bag B are blue?
5 m
Level 3
There are 25% more red crayons than blue crayons in a bag. After John removed 40% of the red crayons and increased the number of blue crayons by 10%, there are now 70 fewer red crayons than blue crayons. Find the number of blue crayons at first.
4 m
Level 3
Container A contains 480 blue buttons and 590 purple buttons. Container B contains 590 blue buttons and 410 purple buttons. How many blue buttons and purple buttons must be removed from Container B to put into Container A so that 50% of the buttons in Container A are blue and 60% of the buttons in Container B are blue?
5 m
Level 3
Sarah had 70% as many candies as Xuan. Sarah gave away 10% of her candies and Xuan bought another 99 candies. As a result, Sarah now has 30% as many candies as Xuan. Find the number of candies that Xuan had at first.
5 m
Level 3
Copier A prints at a rate of 105 leaflets in every 3 minutes and Copier B prints at a rate of 136 leaflets in every 4 minutes. At 2 p.m., both copiers started printing. After a while, Copier A stopped printing for some time as the ink cartridges were being changed before it continued to print again. Copier B continued printing during this time. At 4 p.m., the total number of leaflets printed during the past two hours was 7930. Express the number of leaflets printed by Copier A as a percentage of the total number of leaflets printed by both copiers. Round off the answer to 2 decimal places.
5 m
Level 3
A philanthropist bought a total of $19380 worth of toys, textbooks and clothes to donate to the needy children. The number of clothes bought was 20% more than the number of toys bought but 20% fewer than the number of textbooks bought. The toy cost $12 each and was $2 more expensive than each textbook but 40% cheaper than each piece of clothes. How many toys and textbooks did the philanthropist donate to the needy children?
5 m
Level 3
Tammy baked 420 pies. 40% of them were peach pies. How many more peach pies must Tammy bake so that 80% of her pies are peach pies?
5 m
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%.
  1. How many boys were there at first?
  2. What percentage of the children at the playground were boys in the end? Express your answer as a mixed number.
5 m