We are given that Sasa had some 20-cent and 50-cent coins. The total number of coins is $x$, and they are divided as follows:

• $\frac{7}{8}x$ are 20-cent coins.
• $\frac{1}{8}x$ are 50-cent coins.

Step 1: Determine the initial number of coins

The number of 50-cent coins is $\frac{1}{8}x$. After spending $72.50 worth of 50-cent coins, we know Sasa spent 145 50-cent coins, so:

$\frac{1}{8}x = 145$

Multiplying both sides by 8:

$x = 145 \times 8 = 1160$

Thus, the total number of coins $x$ is 1160.

Step 2: Determine the initial number of 20-cent and 50-cent coins

• The number of 20-cent coins is $\frac{7}{8} \times 1160 = 1015$.
• The number of 50-cent coins is $\frac{1}{8} \times 1160 = 145$, which matches the information given.

Step 3: Spending 50-cent and 20-cent coins

• Sasa spent all 145 of the 50-cent coins.
• Sasa spent $\frac{5}{7}$ of the 20-cent coins, so the number of 20-cent coins she spent is:

$\frac{5}{7} \times 1015 = 725 \text{ (20-cent coins spent)}.$

Thus, the number of 20-cent coins remaining is:

$1015 - 725 = 290.$

Step 4: Calculate the number of remaining coins

After spending the coins, Sasa had $\frac{2}{7}x$ coins left. Since $x = 1160$, the number of remaining coins is:

$\frac{2}{7} \times 1160 = 331.43 \approx 331 \text{ coins (rounded)}.$

Step 5: Calculate the total amount of money left

Sasa has 290 remaining 20-cent coins and 0 50-cent coins left (since she spent all of them). The total value of the remaining 20-cent coins is:

$290 \times 0.20 = 58 \text{ dollars}.$

Thus, Sasa has $58 left.

Final Answer:

Sasa has $\mathbf{58}$ dollars left.

Do you want more details or have any questions?

Here are 5 related questions for practice:

1. If Sasa had 50 more 20-cent coins, what would the total value of her remaining coins be?
2. How many coins would Sasa have left if she spent 3/7 of her total number of coins instead?
3. If Sasa spent half of her remaining 20-cent coins, how much money would she have left?
4. How many 50-cent coins would Sasa need to spend if she had to use $50 worth of them?
5. What would be the total value of coins if Sasa had double the number of 50-cent coins initially?

Tip: Always verify the relationship between proportions and total values when dealing with problems involving fractions of total quantities.