q) There are tickets numbered from 0000 to 9999 , if the sum of the first 2 digits is equal to the sum of the last two digits then the ticket is said to be lucky. Find the probability tht a ticket drawn at random would be lucky.

I think the ans is 29/50.My method is

SUM                   tot no. of numbers

0                                          1²

1                                          2²

2                                          3²

.

.so on

9                                         10²

10                                        9²

11                                        8²

so on

18                                        1²

So,the total no. of numbers are 2(1²+2²+....+9²)+10²=5800

Hence the probability is 5800/10000=29/50

67/1000

@ allamraju:

how is this:

"So,the total no. of numbers are 2(1²+2²+....+9²)+10²=5800"

i mean the sum is 670 not 5800

Sorry,I made a superb calculation.Thanx computer for correcting me.Now,Francis Is the ans 67/1000

yeah thts the same thing i got...67/1000

the q was already asked with a small variation check

http://www.goiit.com/posts/list/algebra-a-4-digit-number-is-choosen-from-0to9999at-is-probability-39052.htm#282221

 u will find 2 sol.