The gum cost $1.5/2=$<<1.5/2=.75>>.75 per pack
So he pays $.75*2=$<<.75*2=1.5>>1.5 for the gum
He pays $1.5*3=$<<1.5*3=4.5>>4.5 for the candy bars
So in total, he pays $1.5 + $4.5 = $<<1.5+4.5=6>>6
#### 6