Total no. of sandwiches = 480
No. of tuna sandwiches = 3/8*480 = 180 sandwiches
No. of beef sandwiches= 35% of 480
= 35/100*480 = 168 sandwiches
Remaining no. of sandwiches = 480-(168+180) = 132 sandwiches
Let no. of ham sandwiches be 5x
Let no. of cheese sandwiches be 6x
5x + 6x = 132
11x = 132
x = 132/11 = 12
No. of cheese sandwiches = 6x = 12*6 = 72 sandwiches
No. of ham sandwiches = 5x = 5*12 = 60 sandwiches