Question

The ratio of the number of boys and girls in a school of 720 students is 7 : 5. how many more girls should be admitted to make the ratio 1 : 1 ?

a. 110
b. 120
c. 140
d. 150

Answer 1

The current ratio of boys to girls is 7:5 in a school with 720 students. By calculating the number of boys (420) and girls (300), we find that we need to admit 120 more girls to have a 1:1 ratio. The correct answer is b. 120.

Step-by-step explanation:

The question asks for the number of girls that should be admitted to a school to make the ratio of boys to girls 1:1 if the current ratio is 7:5 and the total number of students is 720. The ratio 7:5 means that for every 7 boys there are 5 girls.

Let's calculate the number of boys and girls:

1. Total parts in the ratio = 7 + 5 = 12.
2. Each part represents 720 ÷ 12 = 60 students.
3. The number of boys is therefore 7 parts × 60 = 420.
4. The number of girls is 5 parts × 60 = 300.

To make the ratio 1:1 with 420 boys, we need an equal number of girls. Therefore, we need to add 420 - 300 = 120 girls.

The correct answer is b. 120.