A calculus lecture has 200 students. 75% of the students study math, 15% study physics, and the rest study chemistry.

- On Monday, 20% of the physics students leave, and 6 new chemistry students join.
- On Tuesday, 4 physics students decide to study math instead, but stay in lecture.

After Tuesday, what percentage of the students do not study physics?

Keihaku Mar 7, 2023

#1**+1 **

Out of 200 students, 75% study math, which is 0.75200=<<75.01200=150>>150 students. 15% study physics, which is 0.15200=<<15*.01*200=30>>30 students. Thus, the rest study chemistry, which is 200-150-30=<<200-150-30=20>>20 students.

On Monday, 20% of physics students leave, which means 0.230=<<0.230=6>>6 students leave. Thus, the number of physics students remaining after Monday is 30-6=<<30-6=24>>24 students. Additionally, 6 new chemistry students join, increasing the number of chemistry students to 20+6=<<20+6=26>>26 students.

On Tuesday, 4 physics students decide to study math instead, which means the number of physics students decreases to 24-4=<<24-4=20>>20 students. Furthermore, 4 math students join, increasing the number of math students to 150+4=<<150+4=154>>154 students.

After Tuesday, the number of students who do not study physics is 200-154=<<200-154=46 students. Therefore, the percentage of students who do not study physics is (46/200)100%=23%.

The answer is 23%.

Guest Mar 7, 2023

#3**0 **

Maybe if you didn't cheat on your homework, you wouldn't \(\text{su} \text{ck}\) at math.

Guest Mar 7, 2023

#4**+2 **

On Monday, 75% of the students study math, which means there are 150 math students. 15% of the students study physics, which means there are 30 physics students, and the remaining students study chemistry, which means there are 20 chemistry students.

On Monday, 20% of the physics students leave, which is 6 students, and 6 new chemistry students join, so there are now 24 physics students and 26 chemistry students.

On Tuesday, 4 physics students decide to study math instead, but they still attend the calculus lecture. Therefore, the number of math students increases by 4, and the number of physics students decreases by 4. So, after Tuesday, there are 154 math students, 20 physics students, and 26 chemistry students.

**The percentage of students who do not study physics after Tuesday is (154 + 26)/200 * 100% = 90%. Therefore, 90% of the students do not study physics after Tuesday.**

Guest Mar 7, 2023