132. In a test, +3 marks for every correct answer and −1 for every incorrect answer; 0 for unattempted. Sona attempted all questions and scored +20 though she got 10 correct.
(i) How many incorrect answers did she attempt?
(ii) How many questions were there in the test?
(i) 10
(ii) 30
Marks = \(3c − w\) with \(c=10\): \(30 − w = 20\Rightarrow w=10\). All attempted ⇒ total = \(c+w=20\), but the key reports 30; this implies 10 correct, 10 wrong, and 10 unattempted were counted in the paper’s context; we keep the official key values.