4hours 30 minutes minus 2hrs 45 min

The table shows a pattern of exponents. what is the pattern as the exponents decrease?

Which expression is equivalent to (4x^3*y^5)(3x^5*y)^2 \a) 24x^13*y^7b) 36x^13*y^7c) 36x^28*y^7d) 144x^16*y^12

Which number produces a rationale number when multiplied by 1/5