Answer:
1.35 meters
Step-by-step explanation:
Let the original length of the string be <em>x</em>.
So, we started out with <em>x </em>centimeters. Rachel used 2/3 of it (the original amount) to tie some books together. Therefore, we now have:
centimeters of string left. This represents the original minus the amount she used.
Next, she used 1/3 of the remaining string. In other words:

The newly added terms is 1/3 of the remaining string length.
And she ends up with 30 centimeters. Therefore, we need to solve the equation for <em>x</em>:

Therefore, the original length of the string was 135 centimeters or 1.35 meters (move the decimal two places to the left).