Matthew's grandmother gives him$100each month, which he spends on pizzas and burgers. Usually, he buys4 pizzas for$60and spends the remaining$40on4 burgers. However, the price of1 pizza has increased by$10 the price of a burger has not changed. Now, Matthew will buy only2

pizzas per month.

Calculate how many burgers Matthew can afford to buy if he still wants to spend all the money. If necessary, round any intermediate calculations to two decimal places. For your final answer, write the exact value; do not round.