If a man swims 4 meters upstream at 1 mph and back downstream to the same point at 4 mph, what is his average speed?
ক) 0.8 mph খ) 1.6 mph গ) 2.4 mph ঘ) 3.2 mph
ক) 0.8 mph খ) 1.6 mph গ) 2.4 mph ঘ) 3.2 mph
ক) 15 years খ) 16 years গ) 17 years ঘ) 18 years
ক) 7 meters খ) 14 meters গ) 10 meters ঘ) 6 meters
ক) 0 খ) 9 গ) 8 ঘ) 16
ক) Sunday খ) Tuesday গ) Wednesday ঘ) Monday