Answer:
There were 36 space rocks in total.
Step-by-step explanation:
First, you need to find what fraction of the original rocks are silver.
If 2/3 are purple, then 1/3 of them are not.
If 3/4 of the remaining 1/3 are blue, then 3/4 x 1/3 = 3/12 rocks are blue.
2/3 of the rock are purple, 3/12 of them are blue, and the remaining is silver.
So, you need to do 2/3 - 3/12, then find common denominators so, 8/12 - 3/12 which = 1/12.
This means 1/12 of the rocks are silver. If there are silver rocks, you need to find a suitable equation that needs to be solved.
So:
1/12r = 3
r = 36 silver rocks
There were 36 space rocks in total.
hope this helps :)