What is 1/5 divided by 15

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line

Mila's dog weighs 4 pounds more than 8 times the weight of keiko's dog. which expression could be used to fine te weight of mila's dog?

In a 7th grade class,there is 1 boy for every 2 girls.how many girls are in the class if there are 18 boys