In a library the ratio of sci-fi books to historic fiction is 3 : 7. The ratio of historic fiction books to mystery books is 21 : 8. If there are 81 sci-fi books, how many mystery books are there?

correct answer is option b.

step-by-step explanation:

the true statement about geometric figure is option b that is one line can be drawn through all three points.

if three points are on the same plane, they can be connected by a line.

7,24

step-by-step explanation:

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.