Gary, Ivan and Martin are doing arithmetic problems. The number of problems Gary does is three times that of Martin, and the number of problems Ivan does is two times that of Gary. Ivan does 15 to more problems than Martin. How many questions did they do altogether? 
选项为:A:$$25$$  B:$$15$$  C:$$20$$  D:$$35$$  E:$$30$$  请回答其中一个选项.