The speed of a boat in still water is 12 km/hr. If the upstream speed of the boat is 4 km/hr, then what is the speed of the stream?

• (अ)1. 10 km/hr
• (ब)2. 8 km/hr✓ योग्य उत्तर
• (क)3. 5 km/hr
• (ड)4. 3 km/hr