In a certain code language, 'take this vaccine' is written as '892', 'vaccine protects us' is written as '263', and 'take us safe' is written as '593'. How will 'safe vaccine' be written in that language?

25

Given; In a certain code language, 'take this vaccine' is written as '892', 'vaccine protects us' is written as '263', and 'take us safe' is written as '593'. 

So,

take  this  vaccine  =  8  9  2

vaccine  protects  us  =  2  6  3

take  us  safe  =  5  9  3

Thus,

Code for safe and vaccine is 5,2

Therefore, 25 is correct.