How many 5 digit numbers can be formed by using 3, 4, 5, 6, 7, if 6 is necessarily taken at hundred's place and 4 is not allowed at unit's place? Note : Repetition of numbers is not allowed.

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.