In a certain code language, 'x' represents '+', '÷' represents 'x', '-' represents '÷' and '+' represents '-'. Find out the answer to the following question.
Present age of R and S are in the ratio of 3 : 2 respectively. If the present age of H is 117 years and R’s present age is 4/13 of H’s present age, then after how many years the ages of R and S would be in the ratio of 15 : 11?