Hi Team,

In this question I understand Greg mentioned to choose table method and solve. But why cant we apply the formula, i.e. total=A+B-both where A = son in house B=daughter in house, basis the question.

100=80+40 -both which gives both as 20 and hence answer should be C, which is not the case. Correct answer is D.

I understodd the table method as explained by Greg, but just want to know that why do we not get the answer by applying the above formula?