There are 15 students on the bus and 10 are girls.
Then the boys on the bus are
[tex]15-10=5[/tex]So there are 5 boys and 10 girls on the bus.
The ratio of boys to girls is
[tex]\frac{\text{boys}}{\text{girls}}=\frac{5}{10}=\frac{1}{2}[/tex]Therefore, the ratio of boys to girls is 1/2
This means that the boys are one-half as compared to the girls.