The value of the given expression is 
Solution:
Given expression is
.
Let us first convert mixed fraction into improper fraction.

Substitute this in the given expression.


To simplify the above expression, 21 and 60 are cancelled by 3.

Do cross multiplication to make the denominator same.



The value of the given expression is 
Answer:
256= 4 power 4 and 125 = 5 power 3
Should be true. The coffee would not stay the same temperature as it was originally than it would over time.