## need the solution

For discussing Olympiad Level Combinatorics problems
kh ibrahim
Posts: 17
Joined: Mon May 09, 2016 11:18 am

### need the solution

x takes part in three subjects physics, chemistry and mathematics.Each of the subjects is of 100 marks.How many ways can he obtain 200 out of 300?

Abdullah Al Tanzim
Posts: 9
Joined: Tue Apr 11, 2017 12:03 am
I think it is $\frac {102.101}{ 2}$. Notice if you get o in physics then you will have only one way to get 200 marks in the three subjects.if you get 1 in physics then you will have 2 ways and for 2 you will have 3 ways and it will go on for o to 100 ..It forms a series that
$1+2+3+.............+101$ and the sum of the series is $\frac {102.101}{2}$...