Question

In a class of 55 students, 15 students liked Maths but not English and 18 students liked English but

Answer 1

Easy!
You take the total number of students (55) then you remove the people that only like math and remove the people that only like English and remove the people that like none of them and what’s left is how many like both subjects.

55-15-18-5=17 students that like both subjects!