Shreya Shruti, a student of DAV NIT school in Adityapur, 3 km from here, adjoining Saraikela-Kharswan district, secured 66.8%, school sources said.
The girl had taken the extreme step as she apprehended that she had not fared well in her Mathematics and Science subjects, police said.
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She got just pass mark (33) in Maths but secured 62% in Physics and 60% in Chemistry and 84% in Computer Science, sources said.
The results of the CBSE examinations were declared Wednesday.
Shreya had leapt from the 5th floor of the residential apartment situated near the main thoroughfare on Sher-E-Punjab chowk early on Tuesday, police said, adding that two suicide notes addressed to her mother and brother were recovered from the spot.
Shreya had mentioned in the suicide note that she did not fare well in maths and science subjects and also apologised to her family for taking the extreme step, police said.