To find the total amount of time \( t \) that Nate's family spends at Mount Rushmore, we use the information given in the problem.
They watch a movie for \( \frac{1}{4} \) of an hour, which accounts for \( \frac{1}{5} \) of the total time spent at Mount Rushmore.
We can set up the equation using the relationship between the part and the whole: \[ \frac{1}{5}t = \frac{1}{4} \]
Now, to solve for \( t \), we can multiply both sides of the equation by 5 to eliminate the fraction on the left side: \[ t = 5 \times \frac{1}{4} \]
Calculating the right side: \[ t = \frac{5}{4} \text{ hours} \]
To convert \( \frac{5}{4} \) into hours and minutes, we can convert it to a mixed number: \[ \frac{5}{4} = 1 \frac{1}{4} \text{ hours} \] This means Nate's family spends 1 hour and 15 minutes at Mount Rushmore.
Therefore, the total amount of time \( t \) that Nate's family spends at Mount Rushmore is: \[ \frac{5}{4} \text{ hours} \quad \text{or} \quad 1.25 \text{ hours} \]