6) A geologist collects rocks. He has three types, sedimentary, metamorphic and igneous. The ratio of sedimentary rocks to metamorphic rocks is 2:3.
The ratio of metamorphic to igneous is 9:10.
What is the ratio of sedimentary to igneous?

3:5

Step-by-step explanation:

s:m = 2:3

m:i = 9:10

convert m to same number so they are comparable

s:m = 6:9   (multiple so the ratio is still the same as 2:3)

m:i = 9:10 (the same thing as before)

s:i = 6:10

s:i = 3:5 (simplify)

the correct answer is the second option