89,because if you try dividing 373 by 5 it’s 74, so first try adding 77 to 373 which is 450 and divide that by 6 which is 75. Now what you have to do is to add numbers to 373 and divide it by 6 until you get an average of 77. Ex: 373+78=451 451 divided by 6 is 75.16 which isn’t right so you just keep trying different numbers
