Question

How many positive odd integers between 100 and 10000 can be formed using the digits 2,3,4,5 and 6

Answer 1

in the ones place two. 3, 5

note: --- in higher places can be zero, like 010 = 10 so 10 of them

in the tens place ten so 20 to date
in the hundreds place ten so 200
in the thousands place ten so 2000
10003 is too big so none allowed in ten thousands place
so I get 2000