in one hour , a boat goes 11 km along the stream and 5 km against it . find the speed of the boat in still water
"explanation : we know we can calculate it by 1 / 2 ( a + b ) = > 1 / 2 ( 11 + 5 ) = 1 / 2 ( 16 ) = 8 km / hr answer is c"
divide(add(11, 5), const_2)