Level 3
20% of the people are performers for a concert and the rest are spectators. 80% of the spectators are adults and there are 3900 more adults spectators than children spectators. How many adult spectators must leave so that 25% of the people in the concert are adult spectators?

Level 3
Last month Mr Zhang gave his wife, Anna $4000 for household expenditure. Anna spent 60% of the sum on rental, 30% on food and saved the rest. This month, Mr Zhang reduced the sum he gave to Anna. Anna spent the same amount on rental and reduced the amount she spent on food by 30%. She saved the remaining 10% of the sum given to her this month. By what percentage was the sum given to Anna reduced?

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?

Level 3
20% of Nick's savings was $120 more than 30% of Will's savings. After Nick spent ²₃ of his savings and Will spent 40% of his savings, Nick had $13 more than Will. How much was Nick's saving at first?

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?