Question

A class contains 40 students. 21 students own a Math book, 27 students own a Science book, and each student owned at least one of the two text books. Determine the number of students who owned Math and Science textbooks. *

Answer 1

number of student own only math 21

and science 27 ( 6 extra than math)

and rest have each one ofdthe book

so we can say than only 21 of the 40 student have both