New Delhi, Nov. 21 -- The Central Board of Secondary Education (CBSE) does not expect more than 40% of Class 10 students who appear in the first mandatory exam in mid-February to sit for the optional second examinations in May, board chairperson Rahul Singh said on Thursday. CBSE will not allow students to split their attempts across the two cycles to preserve the seriousness of first exam, he said. A student who is absent in three or more subjects in the first exam beginning from February 17 will not be allowed to sit for the second examination to improve their marks, Singh said, addressing a webinar on the CBSE two-board exam scheme. "In the first board exam in Class 10, the total number of answer books which are evaluated by the board co...