Tell me the most scoring chapters in maths and chemistry..... And some hacks to solve mcq also...

scoring chapters from inter 1st year in iit to get atleast below 2000 raks

iam a very average student...and i want to crack jee mains 2021...in this last 7days figure me out on which easy topics i should focus for better score

Two parallel beams of light P and Q are incident normally on a prism and the transmitted rays are brought to focus with the help of a convergent lens as shown. If the intensities of the upper and lower beams immediately after transmission from face AC are 4I abd I, respectively, find the resultant intensity at the focus.

The system of connected flexible cables shown in the figure is supporting 2 loads of 550N and 600N at points B and D. Determine the tensions in various segments of the cable