According to a survey conducted in a locality. all the persons are employed in either manu- facturing, teaching or IT sectors. There are 100 persons working in manufacturing sector, working in teaching sector and one person working only in IT sector. Totally 10 persons work in both IT as well as teaching sector and 6 persons work in teaching sector as well as in manufacturing sector. Also 20 persons are employed in at least 2 sectors types. Find the population of the locality surveyed.
5 pencils and 7 pens together cost Rs 50 whereas 7 pencils and 5 pens together cost Rs 46. Find the cost of one pencil and that of one pen