As the exponent is negative, we can rewrite the expression as (125/64) raised to the power 2/3.
So, (125/64) raised to the power 2/3 can also be written as [(5/4) raised to the power 3] raised to the power 2/3. The exponents will multiply and the final exponent will be 2.
Hence the answer will be (5/4) squared.
Therefore the answer is (24/16).
I may be wrong but I think it is "True"
Needed gallons for 18 miles = 1
Needed gallons for 200 miles = (1/18)*200
= 11.11 gallons