Answer:
1 euro = $1.25
Explanation:
if  3Ib of coffee cost $5
while exchange rate is .8euro = $1
therefore 3Ib coffee in euro will be  .8 * 5 = 4euros
and 3Ib coffee cost 7euros
while exchange rate is .8euro = $1
therefore 3Ib coffee in dollar will be 7 *1 / .8 = $8.75
now 7euro = Â $8.75
    4 euros will be equal to 4 * 8.75 / 7 = $5
so if 7 euros = $8.75 and
    4 euros = $5
therefore 1 euro will be 1 * 5 / 4 = $1.25