Level 3
The ratio of the number of $2-notes to $10-notes in Dana's bag was 1 : 3. Dana exchanged 14 pieces of $10-notes for $2-notes. She then had an equal number of $2-notes and $10-notes. What was the total value of $2-notes and $10-notes in Dana's bag at first?

Level 3
A coin bank contains some twenty-cent and fifty-cent coins in the ratio of 4 : 5. When 16 fifty-cent coins were taken out and replaced by some twenty-cent coins, the ratio became 8 : 7. The total value of the twenty-cent coins added was the same as the total value of the fifty-cent coins taken out. Find the sum of money in the coin box.

Level 3
Sarah bought a total of 300 big and small candies. Then she decided to exchange 60% of her big candies for the small ones in the ratio of 3 : 5. After the exchange, she had 366 candies. What percentage of the candies she bought were small ones?

Level 3
The number of 20-cent coins in a basket was 100% more than the number of 10-cent coins. 13 twenty-cent coins were taken out and exchanged for 10-cent coins. The number of 20-cent coins became ⁵₈ less than the number of 10-cent coins. How much money is there in the basket?

Level 3
Vincent has some 20-cent coins and 50-cent coins which amount to more than $20 but less than $54. The number of 20-cent coins is ¹₄ of all the coins he has. When he exchanges some 50-cent coins for 20-cent coins, the ratio of the number of 50-cent coins to 20-cent coins he now has become 1 : 6.

1. What is the largest possible amount of money Vincent has?
2. What is the total value of 50-cent coins that has been exchanged for 20-cent coins? Express the answer to 2 decimal place.