In a certain code language, 'your attention please' is written as 'puw cuw zuw', 'kind attention' is written as 'muw zuw', and 'please pay attention' is written as 'puw zuw ruw'. How will 'pay' be written in that language?

ruw

Given; In a certain code language, 'your attention please' is written as 'puw cuw zuw', 'kind attention' is written as 'muw zuw', and 'please pay attention' is written as 'puw zuw ruw'. 

So,

your  attention  please  =  puw  cuw  zuw

kind  attention  =  muw  zuw

please  pay  attention  =  puw  zuw  ruw

Thus, pay is coded as "ruw"