Let's assume the total number of students in the tuition center as "T".
Given that 70% of the students have studied Maths, which means 0.7T students have studied Maths.
Similarly, 30% of the students have studied English, which means 0.3T students have studied English.
Also, given that all students who studied English also studied Maths. So, the number of students who studied only Maths will be 0.7T - 0.3T = 0.4T.
Now, we know that 150 students did not study both subjects.
Let's represent the number of students who studied both subjects (Maths and English) as "x".
So, the number of students who studied only Maths will be (0.7T - x) and the number of students who studied only English will be (0.3T - x).
According to the given information, the total number of students who did not study both subjects is 150.
Therefore, we can write an equation as:
0.7T - x + 0.3T - x + x = T - 150
Simplifying this equation, we get:
1.4T - x = T - 150
0.4T = x - 150
Now, substituting the value of x = 0.3T (as all students who studied English also studied Maths), we get:
0.4T = 0.3T - 150
0.1T = 150
T = 1500
So, the total number of students in the tuition center is 1500.
Now, the number of students who studied only Maths will be (0.7T - x) = 0.4T = 0.4 × 1500 = 600.
Therefore, 600 students studied Maths but not English.