Mathematics question(venn diagram) ; a final year maths student was given a project to identify which of 30 chemical substance contained the element iron, lead, and proporous in his project defence, he gave the following breakdown iron only (5), lead and phoporous (10), and the three elements (6), iron and lead (6), iron and proporous only (3). the number of substance that have only phoporous or only lead are equal assuming the elements are the only constituents; (a) how many substance have lead 0nly. (b) how many substance had at least two element