Answer
$P(correct~order)=\frac{1}{120}\approx0.00833$
Work Step by Step
First let's find the number of ways the child can organize the books:
$n!=5!=5\times4\times3\times2\times1=120$
But, there is only one correct way to organize the books:
$P(correct~order)=\frac{1}{120}\approx0.00833$
