Step-by-step explanation:
First convert the amount of dough into an improper fraction:
[tex]3\frac{3}{4}\:\text{lbs} = \dfrac{15}{4}\:\text{lbs}[/tex]
Each roll is 1/8 lb so divide the amount of dough by this amount:
[tex]\dfrac{\left(\dfrac{15}{4}\:\text{lbs}\right)}{\left(\frac{1}{8}\:\text{lb/roll}\right)} = \left(\dfrac{15}{4}\:\text{lbs}\right)\cdot \left(8\:\dfrac{\text{roll}}{\text{lb}}\right) = 30\:\text{rolls}[/tex]