Answer:
Number of Vehicles in parking lot = 10 [ 3 SUV + 7 Trucks]
Probability of an event = [tex]\frac{\text{Total favorable outcome}}{\text{Total possible outcome}}[/tex]
Probability of choosing 7 Vehicles in a parking spot out of [10 vehicles=3 SUVs and 7 trucks] such that it has 2 SUVS and 5 trucks or 3 SUVS and 4 trucks = [tex]\frac{_{2}^{3}\textrm{C}\times_{5}^{7}\textrm{C}+ _{3}^{3}\textrm{C}\times_{4}^{7}\textrm{C}}{_{7}^{10}\textrm{C}}=\frac{3\times21+35}{120}=\frac{63+35}{120}=\frac{98}{120}=\frac{49}{60}[/tex]
Use this formula to find , C(n,r)= [tex]\frac{n!}{(n-r)!r!}[/tex]
C(3,2)=3, C(7,5)=21, C(7,4)=35,C(3,3)=1,C(10,7)=120
