A man goes downstream with a boat to some destination and returns upstream to his original place in 5 hours. If the speed of the boat in still water and the stream are 10 kmph and 4 kmph respectively, the distance of the destination from the starting place is:

• ক 16 km
• খ 25 km
• গ 21 km ✅ সঠিক উত্তর
• ঘ 18 km