Question

Of the students attending a school party, 60% of the students are girls, and 40% of the students like to dance. After these students are joined by 20 more boy students, all of whom like to dance, the party is now 58% girls. How many students now at the party like to dance?

Answer 1

Answer:

252 students at the party like to dance

Step-by-step explanation:

Given:

60% of the students are girls

40% of the students like to dance

20 more boy students

Percentage of the girls in the party = 58%

To Find:

How many students now at the party like to dance=?

Solution:

Let the number of girls be g.

Let the number of total people originally be t.

We know that

$\frac{g}{t}=\frac{60}{100}$

$\frac{g}{t}=\frac{3}{5}$----------------------------------(1)

We also know that

$\frac{g}{t+20}=\frac{58}{100}$

$\frac{g}{t+20}=\frac{29}{50}$-----------------------------(2)

We now have a system of equation from (1) and (2)

3t=5g

$g = \frac{3t}{5}$ ------------------------(3)

50g=29t+580------------------------(4)

Substituting 3 in 4, we get

$50(\frac{3t}{5})=29t+580$

$(\frac{150t}{5})=29t+580$

$30t =29t+580$

$30t -29t = 580$

t =589

So originally there was 580 students

In this 580 students 40% liked to dance

Then the number of students liked to dance =

=> $40\% \text{of} 580$

=>$\frac{40}{100} \times 580$

=>$0.4 \times 580$

=> 232

We also know that with these people, 20 boys joined, all of whom like to dance.

Now the number of students like to dance  = 232+20 = 252 students