Let the number be H T O. Ones digit = O Given that. O =10−5 ⇒ O =5. Also is given that tens digit T is 2 more than ones digit O ⇒ tens digit T = O +2=5+2=7. ∴ The number is. H 75. Given also is that "number is less than 200 and greater than 100 " ⇒ H can take value only =1. We get our numberas 175.