A boat takes 12 hours to go downstream and it takes 24 hours to return to same distance. Find the ratio of the speed of boat in still water to the speed of stream. एक नाव धारा के अनुप्रवाह जाने में 12 घंटे का समय लेती है और उसी दूरी को वापस आने में 24 घंटे लेती है। नाव की स्थिर जल में चाल की धारा की चाल से अनुपात ज्ञात कीजिए।

Let boat speed in still water be b and stream speed be s. Downstream speed = b + s, upstream speed = b - s. Time is inversely proportional to speed for same distance. Given downstream time = 12 hours, upstream time = 24 hours, so upstream takes twice as long, meaning upstream speed is half of downstream speed. Therefore: (b - s) = 1/2(b + s). Solving: 2b - 2s = b + s, so b = 3s, giving ratio b:s = 3:1. We can verify: if b = 3k and s = k, downstream speed = 4k, upstream speed = 2k - indeed upstream is half of downstream.