16-08-2005, 02:38 AM
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Originally Posted by thakarsagar
No suresh, i know the answer for this....but i have not been able to derive it fully...i thought on the following lines...
We need to find it for all the subsets of 1 5 10 and 25 ie 16-1 sets...
using anyone of 1 , 5 10 and 25 -> 4 ways
using 1 and 5 -> 19C1 ways...(its equivalent to solving the equation a + 5b = 100...Now this is limited by the highest coefficient...so divide 100/5 = 20...now any of this 20 i can form a partition...one part been paid by 5 rupee notes and other by 1 rupee notes...)
using 1 and 10 -> 9C1 ways...
using 1 and 25 -> 3C1 ways ...
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See, if you can work this ways...
-sagar
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NOT QUITE SURE ABOUT BELOW but looks correct to me. . SAGAR could you please confirm the answer.
using anyone of 1 , 5 10 and 25 -> 4 ways
(1,5) = 19 ways ( As 5 has to be used so we can subtract 5 from 100. Rest 95 can be distributed in 95/ 5 = 19 Ways)
(1,10) = 9 Ways ( As above)
(1,25) = 3 Ways (As above)
(1,5, 10) = 17 ways ( 5 + 10 = 15. so 100 - 15 = 85) and 85/5 = 17/
(1,5,25) = 14 Ways
(5, 10) = 18 Ways
(5,25) = 15 Ways
(5, 10,25) = 13 Ways
(10,25) = 5 Ways ( because we have to use 2 25's in this case)
So total = 117 ways
Mohit