We can write 4 using three lines(iv). How can we write 1 using five lines?

Question

How many numbers of five digits can be formed by using 1,2,3,4,5, if 4 is necessarily taken at hundred's place and 2 is not allowed at unit's place.
Repetition of number is not allowed.

Answer 1

[V/V] is 5/5 =1.
V - 2 lines each
/ - 1 line.