we are given

Firstly, we will factor numerators and denominators

we can see that
n^2 -6 is factor on both numerator and denominator
so, it will get cancelled
and n^2 -6 can not be equal to 0
so, one of restriction is


we can simplify it

we know that denominator can not be zero


so, option-B.......Answer
We have an equation: 56/? = 4/100
Cross multiply:
4*? = 56*100
⇒ ? = 56*100/4 = 1,400
There are 1,400 blank days~