retagged by
564 views

1 Answer

2 votes
2 votes

Let the number of boys appearing for admission be $x,$ therefore the number of girls appearing for admission be $2x.$

Then the total number of students $ = (x+2x) = 3x$

  • The number of girls get admission $ = \frac{30}{100}\times2x = \frac{3x}{5}$
  • The number of boys get admission $ = \frac{45}{100}\times x = \frac{9x}{20}$

The total number of students who get admission $ = \left(\frac{3x}{5} + \frac{9x}{20}\right) = \frac{21x}{20}$

  • The number of girls who do not get admission $ =  \left(2x-\frac{3x}{5}\right) = \frac{7x}{5}$
  • The number of boys who do not get admission $ =  \left(x-\frac{9x}{20}\right) = \frac{11x}{20}$

The total number of students who do not get admission $ = \left(3x – \frac{21x}{20}\right) = \frac{39x}{20}$

$$\text{(or)}$$

The total number of students who do not get admission $ = \frac{7x}{5} + \frac{11x}{20} = \frac{28x + 11x}{20} = \frac{39x}{20}$

$\therefore$ The percentage of candidates who do not get admission $ = \left(\dfrac{\frac{39x}{20}}{3x} \right)\times 100\% = \dfrac{13}{20} \times 100\% = 65 \%. $


$\textbf{Short Method:}$ Let the number of boys appearing for admission be $100,$ therefore the number of girls appearing for admission be $200.$

Then the total number of students $ = 100+200 = 300$

  • The number of girls get admission $ = \frac{30}{100}\times 200 = 60$
  • The number of boys get admission $ = \frac{45}{100}\times 100 = 45$

The total number of students who do not get admission $ = 300-(60+45) = 300-105 = 195$

$\therefore$ The percentage of candidates who do not get admission $ = \dfrac{195}{300} \times 100\% = 65\%.$

Correct Answer $:\text{D}$

edited by
Answer:

Related questions

3 votes
3 votes
1 answer
1
go_editor asked Mar 13, 2020
839 views
Arun's present age in years is $40\%$ of Barun's. In another few years, Arun's age will be half of Barun' s. By what percentage will Barun's age increase during this peri...
2 votes
2 votes
1 answer
3
1 votes
1 votes
1 answer
5
go_editor asked Mar 13, 2020
661 views
An elevator has a weight limit of $630$ kg. It is carrying a group of people of whom the heaviest weighs $57$ kg and the lightest weighs $53$ kg. What is the maximum poss...