The cat nursery is open two times a day.  hour at noon and  hour in evening. How much time is the cat nursery open everyday

The correct answer is: 13/12 hours

Number of hour cat nursery open in noon = hour.
Number of hour cat nursery open in evening = hour
Time cat nursery open everyday =+.
first we need to find common denomitator for 3 &12
Multiples of 3=3,6,9,12,15
Multiple of 12=12,24,36,48,60,…
∴ common denominator =12.
Now, 

∴ hours cat nursery open everyday