Sasa had some 20-cent and 50-cent coins.

7/8 of the coins were 20-cent coins and the rest were 50-cent coins.After Sasa had spent $72.50 worth of 50-cent coins and 5/7 of the 20-cent coins, she had 2/7 of the coins left. Find the total amount of money Sasa left.

let there be:

c coins
t 20¢ coins
f 50¢ coins

7/8 c = t
1/8 c = f
so, t = 7f

72.50 is 145 of the 50¢ coins
(f + t) - 145 - (5/7 t) = 2/7 (f+t)

since t = 7f,

f + 7f - 145 - 5f = 2/7 * 8f
f = 203
so, t = 1421
and 1624 coins in all

check:
1624 - 145 - 5/7 (1421)
= 1624 - 145 - 1015
= 464

464 is 2/7 of 1624

Thank you, Steve.

The first answer is wrong. What is being asked is the amount. 464 is too much compared to $72.50 which is the combination of 50c and 5/7 of 20c.

Listing method is used to find the answer.

The total fraction for the 20c and 50c is 8/8.
7/8 were 20c
1/8 were 50c

Singaporean Math is applied using the block method.
7 units = 20c
1 unit = 50c
8 units in all

If the denominator is 8, find a multiple that will match the given amount of $72.50. The multiple is equivalent to 1 unit.

The multiple is 48.
Each unit is 48.
$72.50 is 5units of 20c and 1unit of 5c.

48 x 5 x .20 = $48
48 x .50 = $24
$48 + $24 = $72
Add .50 to make it $72.50

The question is the total amount of money left which 2/7.
So that is 48 x 2 x .20 = $19.20

48 48 48 48 48 48 48 49
20c 20c 20c 20c 20c 20c 20c 50c

There is a total of 336pcs 20c coins amounting to $67.20 and
49pcs 50c coins amounting to $24.50
=$91.70 - $19.20 = $72.50

All 50c were spent. Only 2/7 of 20c were left.

To find the total amount of money Sasa left, we need to follow a step-by-step approach:

Step 1: Determine the number of coins Sasa had initially.
Let's assume that Sasa had a total of "x" coins.

Step 2: Calculate the number of 20-cent coins using the given information:
7/8 of the coins were 20-cent coins.
So, the number of 20-cent coins would be (7/8)*x.

Step 3: Calculate the number of 50-cent coins using the given information:
The rest of the coins after subtracting the 20-cent coins would be 50-cent coins.
So, the number of 50-cent coins would be x - (7/8)*x.

Step 4: Calculate the amount of money spent on 50-cent coins:
Sasa spent $72.50 worth of 50-cent coins.
Since each 50-cent coin is worth $0.50, the number of 50-cent coins spent would be $72.50 / $0.50.

Step 5: Calculate the number of 20-cent coins remaining:
5/7 of the 20-cent coins were spent.
So, the number of 20-cent coins remaining would be (2/7) * (7/8) * x.

Step 6: Calculate the number of 50-cent coins remaining:
The total number of 50-cent coins remaining would be the initial number of 50-cent coins minus the number of 50-cent coins spent.

Step 7: Calculate the total amount of money Sasa left:
The total amount of money left would be the sum of the value of 20-cent coins remaining and the value of 50-cent coins remaining.

By following these steps, you can find the total amount of money Sasa left.