$\dfrac{A\_8^{8}\times A\_3^{3}}{A\_{10}^{10}}=\dfrac{6}{90}=\dfrac{1}{15}$ 
Seven girls and three boys are standing in a line randomly. What is the probability that three boys are next to each other? 

a) $\dfrac{1}{15}$ 
b) $\dfrac{2}{15}$ 
c) $\dfrac{1}{5}$ 
d) $\dfrac{4}{15}$ 
e) $\dfrac{1}{3}$ 