A candy shop buys rootbeer candies for $3.15 per pound and watermelon candies for $3.75 per pound. They sell their rootbeer candies for $4.75 per pound and their watermelon candies for $5.00 per pound. If r is the number of pounds of rootbeer candies they sold and w is the number of pounds of watermelon candies they sold, what is their profit?