https://preparationpoint.info/solved-past-papers-mcqs/ppsc-past-papers/ppsc-past-papers-2018/excise-taxation-inspector-bs-16-2018-in-additional-directorate-held-on-20-10-2018/at-the-birth-of-his-son-alis-age-is-32-and-after-how-many-years-its-age-becomes-5-times-of-his-sons-age/