Bob and Maria go to the fruit stand together. They have
at most $21 to spend on fruit to make muffins.
Blueberries cost $4 per pound and strawberries cost $3
per pound. They need more than 3 pounds of fruit.
Bob says they should buy 1 pound of blueberries and 3
pounds of strawberries.
Maria says they should buy 2 pounds of each.
Are both of these possible?