Deven has four ducks labeled A, B, C, and D. How many ways are there for Deven to arrange his ducks in a row if duck A must be before duck D?

qwertyuiopasdfghjkl Aug 18, 2020

#1**0 **

Could be ADxx AxDx AxxD xADx xAxD xxAD six ways for A before D

the other two slots have two ways to arrange

6 x 2 = 12 ways

ElectricPavlov Aug 18, 2020