Read the following information carefully to answer the questions given below :
In a college , 600 students of B.Tech are enrolled. The ratio of boys to girls is 7:8 . There are three disciplines , namely Computer Science, Electronics and Electrical, in the college. In Computer Science discipline there are 50% girls of their total number and the boys are 40% of their total
number. In Electronics discipline, girls are 30% of their total number while boys are 30% of their total number. Electrical discipline has girls 20% of their total number and the boys are 30% of their total number. 28 boys and 36 girls are Electronic and Computer Science both . 24 boys and 28 girls are in Electronics and Electrical both . 20 boys and 32 girls are Computer Science and Electrical both. 8 boys and 12 girls are enrolled in all three disciplines .
number. In Electronics discipline, girls are 30% of their total number while boys are 30% of their total number. Electrical discipline has girls 20% of their total number and the boys are 30% of their total number. 28 boys and 36 girls are Electronic and Computer Science both . 24 boys and 28 girls are in Electronics and Electrical both . 20 boys and 32 girls are Computer Science and Electrical both. 8 boys and 12 girls are enrolled in all three disciplines .
1. What percentage of students are enrolled in all three disciplines ?
1.3.3%
2.7.2%
3.8.5%
4.9.32%
5.None of these
2. What is the ratio of boys to girls only in Computer Science discipline ?
1.13.9
2.9:13
3.9:11
4.11:9
5. None of these
3. The ratio of the number of boys in Computer Science and Electrical both to that of girls only in Electrical is
1. 5:3
2. 3:5
3. 5:4
4. 4:7
5. None of these
4. By what per cent is the number of boys in Computer Science discipline more than the number of girls in Electronics discipline ?
1.40/3 %
2.100/3 %
3.50/3 %
4.44/3
5. None of these
5. The ratio of boys to girls enrolled only in Electronics ?
1. 10:11
2. 9:10
3. 7:5
4. 5:7
5. None of these
Answers and Solutions :
Solution :
Total number of students = 600
Number of boys in college = 7*600/15 =280
Number of girls in college = 8*600/15 = 320
Computer Science + Electronics :
Boys = 28
Girls = 36
Electrical + Electronics :
Boys = 24
Girls = 28
Computer Science + Electrical :
Boys = 20
Girls = 32
All three disciplines :
Boys = 8
Girls = 12
Computer Science :
Boys = 40*280/100 = 112
Girls = 50*320/100 = 160
Only boys = 72
Only girls = 104
Electronics :
Boys = 30*280/100 = 84
Girls = 30*320/100 = 96
Only boys = 40
Only girls = 44
Electrical :
Boys = 30*280/100 = 84
Girls = 20*320/100 = 64
Only boys = 48
Only girls = 16
Answers :
1. 1
Total number of students enrolled in all three disciplines = 20
Total number of students = 600
Percentage = (20*100)/600 = 3.33%
2. 2
Ratio = 72 : 104 = 9:13
3.3
Boy both computer science and Electrical = 12+8 = 20
Only girls electrical = 16
Ratio = 20:16 = 5:4
4.3
Percentage = (112-96)*100/96= 50/3 %
5.1
Boy only electronic = 40
Girls only electronic = 44
Ratio = 40:44 = 10:11
