Problem: if soundharya rows 49 km upstream and 77 km down steam taking 7 hours each , then the speed of the stream
Rationale: speed upstream = 49 / 7 = 7 kmph speed down stream = 77 / 7 = 11 kmph speed of stream = ½ ( 11 - 7 ) = 2 kmph answer : c
annotated_formula: divide(subtract(77, 49), multiply(7, const_2))