George buys 2.5 pounds of hamburger and 2 pounds of chicken per week when hamburger costs $4 per pound and chicken costs $5 per pound, and this bundle of goods costs him $20 per week. What wil1 happen if the price of hamburger drops to $2 per pound and the price of chicken increases to $7.50 per pound? [Note that George's original bundle of hamburger and chicken still costs $20 after these price changes.]