how many 4 digit odd numbers less than 6000 can be found usi

how many 4 digit odd numbers less than 6000 can be found using digits 2, 4, 6, 7, 8, 9 ?

Solution

4 digit numbers less than 6000

So 1000th place digit can be:2,4 ie 2 ways

Odd digit. So units place can be:7,9 ie 2 ways

Other two can be filled in 6 ways each

So, 2*2*6*6=144 numbers