EASY MULTIPLE CHOICE math question 10 points!!!!!?

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2. Twenty students from Eastwood High School took a test. Eight of the students obtained grades of D, or below. Some of the students are majoring in the sciences: 10 take Mathematics, 9 take Computer Sciences and 5 take Physics, but none of them take all three subjects. All the students who are taking the above subjects obtained grades of B or C in the test.
Which of the following is false ?
a. No student obtained an A grade
b. At most ten students take two courses
c. At least three students take Physics and Mathematics
d. Seven students take Computer Science and Mathematics
e. Twelve students got a grade of B or C

2. Zhuri wrote down all the positive integers that have at most seven digits and contains only the digits 0 and 1. How many times did she write down the digit 1?
a. 128 b. 224 c. 288 d. 448 e. 512