The chance that a student is looking at stars is 30%. 30% of 4 is [tex] \frac{6}{5} [/tex]. Since they ask about 2 students it is [tex] \frac{6}{5} * \frac{6}{5} = \frac{36}{25} =1.44%[/tex]
Black holes 40% of 4 is [tex] \frac{8}{5} * \frac{8}{5} = \frac{64}{25} = 2.56%[/tex]
Planets 10% of 4 [tex] \frac{2}{5} * \frac{2}{5} = \frac{4}{25} = 16%[/tex]
Comets 20% of 4[tex] \frac{4}{5} * \frac{4}{5} = \frac{16}{25} = 64%[/tex]
Hope that helps
