Question

In how many ways can the digits of the number 2233558888 be arranged so that the odd digits are placed in the even positions?

Answer 1

even positions=5 so the nos can be placed in 5! ways and 3 is repeated twice and also 5 is repeated twice so... 5!/2!*2!=30
after 4 odd nos are placed then we have 6 positions for other nos to be placed so...same as 6!ways and 2 is repeated twice and 8 is repeated four times... 6!/2!*4!=15
so 30*15=45