The correct answer to my knowledge would be 45.
Assuming that the 10 soils are each represented by A, B, C, D, E, F, G, H, I, J.
A can combine with 9 others as: AB AC AD AE A F AG AH AI AJ
B can combine as: BC BD BE BF BG BH BI BJ
C as: CD CE CF CG CH CI CJ
D as: DE DF DG DH DI DJ
E as: EF EG EH EI EJ
F as: FG FH FI FJ
G as: GH GI GJ
H as: HI HJ
I as: IJ
Once you add all the combinations together, you get 45.
Hoping this helped you!
High frequency, short / small wavelength
The answers are:
Zinc ,Iron , Copper , silver , lead , mercury .
Answer:
C. 200 billion
Explanation:
The milky way galaxy is estimated that there is 200 billion stars