A bakery sells 4 varieties of pastries. John buys 10 pastries making sure, he gets at least one of each kind.
In how many ways can John make the purchase ?	Choose the correct choice from the following options:
A) 84	B) 86	C) 88	D) 90	E) 82
no of 1st variety of pastry: a   no of 2nd variety of pastry: b   no of 3rd variety of pastry: c   no of 4th variety of pastry: d   So, we have a+b+c+d=10 (where a,b,c,d&gt;0)   Remember: Number of positive integer solution of x+y+z+... (r terms) = n is (n-1)C(r-1)   So, the answer to the question would be (10-1)C(4-1) = 9C3 = 84.   84NSWER:84
<result>A</result>
A bakery sells 4 varieties of pastries. John buys 10 pastries making sure, he gets at least one of each kind.
In how many ways can John make the purchase ?