Number of four-digit numbers of the form $N=abcd$  which satisfy following three conditions

i) $4000\le N<6000$  
ii) N is a multiple of 5
iii)  $3\le b<c\le 6$
is_______

We have  

First place a can be filled in 2 ways, i.e.   $4,5(4000\le N<6000)$
For b and c, total possibilities are  $6(3\le b<c\le 6)$
i.e.,  $34,35,36,45,46,56$
Last place d can be filled in 2 ways, i.e.,0,5(N is a multiple of 5)
Hence, total numbers  $=2\times 6\times 2=24$