NWaitforitZ wrote:
There is something wrong here. sandy's explanation is correct, but nowhere does the question say exactly which side of the park is left unfenced. It could well be either length or width of the park. If we consider only length, as sandy writes, sure it is either 120 or 60. But we also have to consider the possibility that the unfenced side is the width, which is either 30 or 60. Hence, 30 has got to be one of the possibilities. Surely, the answers are A, C, E?
option A cannot because it voilates the contraint of 180 unit sum of three side.
let see, 30 unit is unfenced side means other side must be 120. And given condition sum of three side exceed which violate the given condition.