Level 3
A coin bank contains some twenty-cent and fifty-cent coins in the ratio of 2 : 5.
When 10 fifty-cent coins are taken out and exchanged with some twenty-cent coins of the same value,
the ratio became 8 : 9.
Find the sum of money in the coin box in dollars.
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
At the end of May, Xandra had thrice as many 20-cent coins as 50-cent coins in her piggy bank. She took out 70 20-cent coins and exchanged it for 50-cent coins of the same value. In June, she saved another 38 20-cent coins and some 50-cent coins. She then had four times as many 50-cent coins in the end. She had 500 coins in the end. How many 50-cent coins did she save in June?
