Answer:
Therefore the required ways are =190
Step-by-step explanation:
Combination: Combination is the number of selection of items from a collection of items where the order of selection does not matter.
Total number of smartphones =22
Defective phone = 2
Non defective phone = (22-2) =20
The control inspector randomly test 4 smartphones of which 2 are defective.
Non defective phone = 2
The ways to select 2 non defective phone is
[tex]^{20}C_2=\frac{20!}{2!(20-2)!} =\frac{20!}{2!18!}=\frac{19\times 20}{2} =190[/tex]
The ways to select 2 defective phone is= [tex]^2C_2=1[/tex]
Therefore the required ways are = (190×1) =190
