Answer:

Step-by-step explanation:
Given,
Time taken in one rotation of earth = 23 hours, 56 minutes and 4 seconds.
Since, 1 minute = 60 seconds and 1 hour = 3600 seconds,
⇒ Time taken in one rotation of earth = (23 × 3600 + 56 × 60 + 4) seconds
= 86164 seconds,
Now, the number of radians in one rotation = 2π,
That is, 86164 seconds = 2π radians

Hence, the number of radians in one second is 
First we need to multiply to make the fractions have equal denominators so we can add/subtract.
math: 1/3 x 4/4=4/12
science: 1/4 x 3/3=3/12
Now we can find the time she spent on history (I assume this is what you are looking for)
Total time-math time<span>-science time=history time</span>
12/12-4/12-3/12
=5/12
Amy spent 5/12 of her time working on history.