Two joggers left Delhi for Noida simultaneously. The first jogger stopped 42 min later when he was 1 km short of Noida and the other one stopped 52 min later when he was 2 km short of Noida. If the first jogger jogged as many kilometers as the second, and the second as kilometers as first, the first one would need 17 min less than the second. Find the distance between Delhi and Noida?

Correct Answer: 15 km
$$\eqalign{ & {\text{Speed of first Jogger}} \cr & = {\frac{{ {x - 1} }}{{42}}} \times 60\,{\text{kmph}} \cr & {\text{Speed of }}\,{2^{nd}}\,{\text{jogger}} \cr & = {\frac{{ {x - 2} }}{{52}}} \times 60\,{\text{kmph}} \cr & {\text{Then}}, \cr & {\frac{{x - 2}}{{{s_b}}}} - {\frac{{x - 1}}{{{s_b}}}} \cr & \cr} $$
Now, we use option checking method which gives us that option (B) is correct.