the ratio of boys to total of students is 2:5.the number of girls of the student is 3. there are 123 girls.how many boys are there?

123/3=41. 41*2=82 students

To find the number of boys, we need to calculate the total number of students first.

Given that the ratio of boys to the total number of students is 2:5, we can write this ratio as 2x:5x, where x represents a common multiple for both parts of the ratio.

If the number of girls is 123, and it represents 3 parts (since the ratio of boys to total students is 2:5, and girls are the remaining 3 parts out of 5), we can express this relation as:

3 parts = 123 girls

To find one part of the ratio, we can divide 123 by 3:

1 part = 123 / 3

1 part = 41

Now that we know one part represents 41 students, we can calculate the total number of students by multiplying one part by five (as the ratio is 2:5):

Total students = 41 × 5

Total students = 205

As we know that the ratio of boys to the total number of students is 2:5, we can find the number of boys by multiplying the total number of students by the ratio of boys to the total number of students:

Number of boys = 205 × (2/5)

Number of boys = 82

Therefore, there are 82 boys.