Question

Number of girls enrolled in B.Tech.(electronics) forms approximately. What percent of total number of students in the college?

• A. 7%
• B. 13%
• C. 15%
• D. 22%
• E. 24%

Answer 1

The correct option is C 15%

Number of students in the college =7200
Number of boys =$\frac{7}{12}\times 7200=4200$
Number of girls =$\frac{5}{12}\times 7200=3000$
Number of student in B.Tech (nano technology)
=22% of 7200=1584
Number of girls in B.Tech (computer science)
=16% of 3000 =480
Number of boys in B.Tech.(mechanical)=18% of 4200 =756
Number of girls in B.Tech (civil) =30% of 480 =144
Number of boys in B.Tech.(electronics) =15% of 4200=630
Number of boys in B.Tech.(computer science)=50% of 480=240
Number of girls in B.Tech.(aerospace) =15% of 3000=4500
Number of boys in B.Tech.(civil) =$\frac{3}{1}\times 144=432$
Number of students in B.Tech (electronics) =24% of 7200 =1728
$\therefore$ Number of girls in B.Tech (electronics) =1728-630=1098
Number of boys in B.Tech.(aerospace) =$\frac{12}{5}\times 450=1080$
Number of boys in B.Tech.(nano technology) =Remaining
Number of boys =4200-(756+630+240+432+1080)
=4200-3138=1062
$\therefore$ Number of girls in B.Tech (nano technology)
=1584-1062=522
Number of girls in B.Tech.(Mechnical)=Remaining
Number of girls =3000-(480+144+450+1098+522)=3000-2694=306
Tabular form of above information is shown below.
$\begin{array}{ccc}Subjects& Numberofboys& Numberofgirls\\ B.Tech.\left(computerscience\right)& 240& 480\\ B.Tech.\left(mechanical\right)& 756& 306\\ B.Tech.\left(civil\right)& 432& 144\\ B.Tech.\left(electronics\right)& 630& 1098\\ B.Tech.\left(aerospace\right)& 1080& 450\\ B.Tech.\left(naontechnology\right)& 1062& 522\\ Total& 4200& 3000\end{array}$
Number of girls enrolled in B.Tech (electronics)=1098
$\therefore$ Required percentage $=\frac{1098}{7200}\times 100\%$
$=15.25\%\simeq 15\%$