Question 927228
Re TY: Recommend to just try your very best to keep it simple.
This problem a good example. 
We don't want the nickels( Dimes in the 2nd part)..so just don't make them part of the choices
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16coins: 5Q, 3N,2D,6P
How many sets of 5 coins include 2 quarters and no nickels {{{(5C2)(8C3)}}}
How many sets of 6 coins include at least 1 dime 
All choices - choices with NO dimes = {{{16C6 - 14C6}}}