Since these are graphical questions, we will try to eliminate 3 incorrect options instead of choosing the 1 right option.
1Q: For full time students, we can see that the max % of student studying is between 9am - 1 pm.
So any option which has one hour from this range and an hour from another range should be wrong.
Hence C and A are eliminated.
No between rest of the 2 options, at 8 am the % student studying is between 20-25% and at
the % full time student studying at:
8am = 20-25%
8pm = 20-25%
11pm = 10-15%
12am = 5-10%
Also we can see that the slope from 11 pm to 12 am is very steep, hence option D is also eliminated.
Hence
option B is correct.
2Q.
From last q we saw that % full time students studying at 11pm is around 10-15%.
Now again we try to eliminate 3 options
the % part time student studying at:
6am = 0-5%
8pm = 5-10%
10am = 10-15%
11pm = 5-10%
Hence option A,B and D are not similar to the range of % full time students studying at 11pm.
Hence
option C is correct.