haww... mera bhi thik thaa.... 😞 meko tag nhi kia aapne!!! on second thoughts acha kia nhi kia... my method is pretty time consuming.
anyway, this is how i did. all 6 rings in 1 finger 4 for 2 fingers there are 5 cases, 5*4C2 = 30 for 3 fingers there'll be 10 cases. so.. 10 * 4C3 = 40 for 4 fingers ,...10 add all of them.. 84~
suppose a,b,c,d to be four fingers..it is given in question that a finger can have 0 to 6 rings possible. so question translates to "finding the number of non-negative solution of a+b+c+d = 6"
this is case where we need to distribute 6 similar things between 4 different objects(S->D)
a+b+c+d=6
where a,b,c,d represent the fingers( or different objects in which we want to distribute)
now the scenario is you have 9 things(6 +3=9, 6=> is present on RHS, 3=> is the count of plus sign) out which 6 are same(treat them as 1's) and 3 are same (treat them as 0's) and you want to distribute them.
It will take care of all the cases possible.
how you pretty well know how to distribute them..
OA : 9C3=84
This approach can be followed any where where you have a situation of distributing the same things to different objects. It is called as Partition method or one-zero approach.