Do we really need to focus on only Important Questions for class 9th & class 8th for science and maths?

Important questions for 8th and 9th class are one of the most commonly googled terms online. But why do students google about important questions? Students google for important questions so that they can prepare for their exams with really minimum effort and save time. But the question is that if important questions are really enough to prepare for the board exams.