Question

A school has 630 students. The ratio of the number of boys to the number of girls is 3:2. This ratio changes to 7:5 after the admission of 90 new students. Find the number of newly admitted boys.
____
​

Answer 1

Step-by-step explanation:

3:2.3x+2x=630⇒5x=630⇒x=126 2x=2×126=252

Answer 2

GIVEN:-

A school has 630 students. The ratio of the number of boys to the number of girls is 3:2. This ratio changes to 7:5 after the admission of 90 new students.

To Find:-

• The number of newly admitted boys.

Solution:-

Let the number of each student be x.

So,

• Let The Number of Boys=3x
• let The Number of girls=2x

According to the Question:

$3x + 2x = 630$

$= > 5x = 630$

$= > x = \frac{630}{5}$

$= > x = 126$

∴ Number Of boys= $3x = 3 \times 126 = 378$

and,

Number of girls= $2x = 2 \times 126 = 252$

We Know That

New Admission= 90

∴ Total Students=630+90= 720

and the ratios are changed to 7:5

Now,

• Let the Newly Number of boys=7x
• Let the newly Number of girls=5x

According to the Question:

$7x + 5x = 720$

$= > 12x = 720$

$= > x = \frac{720}{12}$

$= > x = 60$

The Number of Newly Admitted Boys=$7x = 7 \times 60 = 420$

And,

The Number of Newly Admitted Girls=$5x = 5 \times 60 = 300$

∴ The number of newly admitted boys are 420.