Question

WILL GIVE BRAINLIEST!!!!!!!!!

Answer 1

Answer:

35

Step-by-step explanation:

PLEASE GIVE ME THE BRAINLIEST... I NEED SOME POINTS...

Answer 2

Answer:

35

Step-by-step explanation:

At the beginning, the ratio number of girls : number of boys is

$\frac{G}{B}=\frac{3}{2}$ (1)

where

G is the number of girls

B is the number of boys

Later, seven more girls join the class, and two boys drop the class, so the new numbers of girls and boys are

$G'=G+7$

and

$B'=B-2$

We are also told that now the ratio is

$\frac{G'}{B'}=\frac{5}{2}$

Substituting the two equations above,

$\frac{G+7}{B-2}=\frac{5}{2}$ (2)

Also, from eq.(1) we can write

$G=\frac{3}{2}B$

And substituting into (2) and re-arranging, we can find B:

$\frac{\frac{3}{2}B+7}{B-2}=\frac{5}{2}\\\frac{3}{2}B+7=\frac{5}{2}(B-2)=\frac{5}{2}B-5\\B=12$

And so

$G=\frac{3}{2}B=\frac{3}{2}(12)=18$

Therefore, the total number of students in the class BEFORE is

$N=G+B=18+12=30$

And so, after we have:

$G'=G+7=18+7=25\\B'=B-2=12-2=10$

So the new number of students is

$N'=G'+B'=25+10=35$