Answer: Option C
Dividend = divisor × quotient + remainder
$$\eqalign{
& {\text{First number }} \cr
& \Rightarrow {\text{ }}\left( {17 \times {\text{n}}} \right) + 13 \cr
& {\text{Let n = 1}} \cr
& \Rightarrow (17 \times 1) + 13 \cr
& \Rightarrow 30 \cr
& {\text{second number }} \cr
& \Rightarrow {\text{ }}\left( {17 \times {\text{n}}} \right) + 11 \cr
& \Rightarrow (17 \times 1) + 11 \cr
& \Rightarrow 28 \cr
& {\text{According to question}} \cr
& = \frac{{30 + 28}}{{17}} \cr
& = \frac{{58}}{{17}} \cr
& \Rightarrow {\text{remainder = 7}} \cr} $$
Alternate :
Divisor = 1st remainder + 2nd remainder - 3rd remainder
$$\eqalign{
& 17 = {\text{ }}13 + 11 - {\text{3rd remainder}} \cr
& {\text{3rd remainder}} = 24 - 17 = 7 \cr} $$