For this you simply need to give both fractions a common denominator!
The easiest way to do this specific problem would be to make the denominator 12. Why 12? Because 4 x 3 = 12.
So:
1/4 --> ?/12 --> 1 (3) / 12 --> 3/12
2/3 --> ?/12 --> 2 (4) / 12 --> 8/12
Total amount of time means the sum (adding them together).
When adding fractions, you MUST have a common denominator! (Which is what we just did).
So 3/12 + 8/12 = (8+3) / 12 = 11/12 hours
Notice how the denominator stayed the same? When adding/subtracting fractions, the denominator stays the same! :)
Hope this helped!
-------------------------------
DISCLAIMER: I am not a professional tutor or have any professional background in your subject. Please do not copy my work down, as that will only make things harder for you in the long run. Take the time to really understand this, and it'll make future problems easier. I am human, and may make mistakes, despite my best efforts. Again, I possess no professional background in your subject, so anything you do with my help will be your responsibility. Thank you for reading this, and have a wonderful day/night!
