Sets Relations And Functions Question 38
Question: Each student in a class of 40, studies at least one of the subjects English, Mathematics and Economics. 16 study English, 22 Economics and 26 Mathematics, 5 study English and? Economics, 14 Mathematics and Economics and 2 study all the three subjects. The number of students who study English and Mathematics but not Economics is
Options:
A) 7
B) 5
C) 10
D) 4
Show Answer
Answer:
Correct Answer: B
Solution:
- [b]C stands for set of students taking economics $ a+b+c+d+e+f+g=40;a+b+d+g=16 $ $ b+c+e+g=22;d+e+f+g=26 $ $ b+g=5;e+g=14;g=2 $ Go by backward substitution $ e=12,b=3,d+f=12,c+e=17\Rightarrow c=5;a+d=11 $ $ a+d+f=18\Rightarrow f=7,\therefore d=12-7=5 $
BETA
