So x*4%=(4500-x)*6%
x=2700
Total return =2700*4%*2=2 16
Therefore, the average interest rate = 216/4500 *100% = 4.8%.
2. Let x = the price of each new bottle of wine, and y = the refund of each returned bottle of wine.
32 16 * x- 1824 * y = 574.56
5208*x-2232*y=944.88
x=0. 19，y=0.02
3. I'm not sure about the following conversion
1 USD = 4 quarters = 10 dimes = 20 nickels =100p.
Use these transformations to calculate the results.
1. 25 = 5 nickels, so the clerk should subtract 4 nickels from the amount.
1diam =10p, so the clerk should add 9 pence.
1 nickels = 5p, minus 4X nickels = 20X pence, and then add 9X pence.
Therefore, the clerk needs to subtract 4X*5-9X= 1 1X pence from the total to get the correct total.