Permutation and Combination problem : In how many ways can Rs. 16 be divided into 4 person when none of them get ... Permutation and Combination problem : 
Problem : In how many ways can Rs. 16 be divided into 4 person when none of them get less than Rs. 3 ? 
I have this : The number of ways of distributing $n$ things all alike into $r$ different groups is $^{n+r-1}C_{r-1}$ lots , no lots being blank: 
Coefficient of $x^n $ in $(1+x+x^2+.....)^r$
I am unable to understand how to use this case in the given problem. Request you to please help me on this and elaborate a bit .. will greatful to you... Thanks...

The easiest way to solve it is to imagine giving each person Rs. $3$ right away and then distributing the remaining Rs. $4$ arbitrarily. In other words, reduce the problem to distributing Rs. $4$ amongst $4$ people with no restrictions: you have the formula for that, with $n=r=4$:
$$\binom{4+4-1}{4-1}=\binom73=35\;.$$
