I answered part A correctly but I struggled with part B. PLEASE HELP!!!!!!

The management of Rocko's Pizzeria is considering a special promotion for the last two weeks of May, which is normally a relatively low-demand period. The special promotion would involve selling two medium pizzas for the price of one, plus 1 cent. The medium pizza normally sells for $11.99 and has variable expenses of $2.8. Expected sales volume without the special promotion is 420 medium pizzas per week. Required: a. Calculate the total contribution margin generated by the normal volume of medium pizzas in a week. b. Calculate the total number of medium pizzas that would have to be sold during the 1-cent sale to generate the same amount of contribution margin that results from the normal volume. Note: For all requirements, do not round intermediate calculations. Round your final answer to the nearest whole dollars. Answer is complete but not entirely correct