5 - digit numbers are to be formed using 2,3,5,7 , 9 without repeating the digits. If p be the number of such numbers that exceed 20000 and q be the number of those that lie between 30000 and 90000 , then p: q is:

Step-by-step solution

p : array llllll 0 & 0 & 0 & 0 & 0 & place 5 & 4 & 3 & 2 & 1 & ways array Total no, of ways =5 !=120 Since all numbers are >20,000 all numbers 2,3,5,7,9 can come at first place. q : array llllll 0 & 0 & 0 & 0 & 0 & place 3 & 4 & 3 & 2 & 1 & ways array Total no. of ways =3 4 !=72 ( 2 and 9 can not be put at first place) So, p: q=120: 72=5: 3