480 x 10/100 = <<480*10/100=48>>48 employees got a salary increase.
480 x 20/100 = <<480*20/100=96>>96 employees got a travel allowance increase.
So a total of 48 + 96 = <<48+96=144>>144 employees got an increase.
Therefore, 480 - 144 = <<480-144=336>>336 employees did not get any increase.
#### 336