You can
put this solution on YOUR website!there are 4 even and 3 odd numbers....
a)
no. of ways to form 4 digit numbers without repetition = 7P4 = 840
b) no. of ways to form 4 digit numbers with repetition = 7*7*7*7 = 7^4 = 2401
c) we can put odd digit on unit place be 3 ways and can arrange remaining 6
digit on first 3 places by 6P3 ways,
no. of odd numbers ( refer to a ) = 6P3 * 3 = 360
d) for unit place we can put digit by 4 ways and for other 3 places any digit
no. of even numbers when repetition is allowed = 7*7*7*4 =1372
