Both the section cover almost 30/100 so 1st thing you can't ignore this. Moving forward strategically you can cover it all and save your time too. 1 Get a good book on Engineering Mathematics for GATE , Made Easy Publication, review small theory and jump to previous year question. If you give full time into it a week will be enough. 2 When you don't understand any particular section and you are not into coaching search that on YouTube there will be several videos on every topic understand it and get back to solving. 3 Don't trouble yourself with time consuming questions. Hope your basics till Intermediate was good. 4 Regarding Aptitude section if you are good in basics jump to previous year question or pick any book like RS Agarwal Quantitative Reasoning, check only examples. 5 For Verbal Questions if you are good in English otherwise IES book on English will be a quick way to cover things, it won't take more than couple of days but again you'll have to revise later. Good Luck!!!