There are 624 students in a school. The ratio of boys and girls in this school is 3:5. Find the total of girls & boys are there in this school?  Choose the correct choice from the following.
A) 320
B) 345
C) 375
D) 390
E) 400
In order to obtain a ratio of boys to girls equal to 3:5, the number of boys has to be written as 3 x and the number of girls as 5 x where x is a common factor to the number of girls and the number of boys. The total number of boys and girls is 624. Hence   3x + 5x = 624   Solve for x   8x = 624   x = 78   Number of boys   3x = 3 × 78 = 234   Number of girls   5x = 5 × 78 = 390   390
<result>D</result>
There are 624 students in a school. The ratio of boys and girls in this school is 3:5. Find the total of girls & boys are there in this school?