so you have 1 of each a penny a nickel a dime and a quarter so the number combos is shown below
1 penny and nickel
2 penny and dime
3 penny and quarter
4 nickel and dime
5 nickel and quarter
6 dime and quarter
The reason why number 4 doesn't say nickel and penny is because is if I had said that it would of been the same as number 1 just that the penny and nickel has switched places so the number of different 2 coin sums are 6
also a penny + a nickel + a dime + a quarter is = to 41 cents