yuppievn

It's clearly that y = 6. Because 25 + 22 + 19 = 66. Assume that if every student took 2 courses so the number would be 60 for 30 students. The number 66 means that at least 6 students have taken 3 courses. Now let's find x. In my views, to find x, we find the greatest number of students WHO took 2 courses and then comparing with the number of students took the 3rd one. First, let find the greatest number of students who takes Math and English among 30 students. We have 25 for Math and 22 for English, thus the number taking both Math and English is 25 + 22 - 30 = 17. And we have 19 History students. Comparing 17 and 19, the greatest number of students that take 3 courses is 17. Repeat with (1) Math and History comparing with English and (2) History and English comparing with Math, then we have the greatest number would be 17. Then we have x + y = 17 + 6 = 23. It is my explanation. Hope that it is correct :D.