Concept:Age-difference problems are solved by expressing all ages in terms of one common variable.Explanation:Let Rohit’s age be x years.Aman is 3 years older than Rohit, so Aman’s age is x+3.Rohit and Danish are twins, so Danish’s age is also x.Aman is 3 years younger than Suresh, so Suresh’s age is (x+3)+3=x+6.Suresh’s age minus Danish’s age is (x+6)−x=6 years.Answer:Suresh is 6 years older than Danish.Correct option: C.