3.80+2.60=6.40$ money that erik need to pay 6.40$ x .05=.32 (.05 represent the 5% coupon) 6.40$ - .32=6.08subtract the percent of the coupon to find the total bill of erik 20$ - 6.08=13.92$ subtract the money that erik needs to the 20$ 13.92$ would be the change that erik receive back
There are an infinite number of these whole numbers. Thus the series goes on without bounds. Whatever very big number you can think of there is another one which is 1 greater.