As it is written, the correct answer would be:
Between 12 and 13 inches.
Step-by-step explanation:
Dividing 51 by 4, we see that 4 goes into 51 12 times. This makes the whole number 12. 12*4 = 48, which leaves 3 left over; this will be the numerator. This means 51/4 = 12 3/4. This would be between 12 and 13 inches.