GMAT Problem Solving (PS) | At Jonah Johnston High School, there are 300 students in the senior

Given that there are total 300 seniors and all the seniors who've opted for precalculus have also opted for physics.
Hence, seniors opting for precalculus but not physics is zero.

Hence total number of seniors:
Not opting for precalculus = 300-x
Not opting for Physics= 100
Opting for physics=200
(As in the image)
Try putting the given alternatives:
Only for E)150,the possibility won't be negative for any case.
Hence,Answer choice E should be correct.
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