Do all the dimes or all the nickels have a greater total value

That depends on how many of each you have.

-- If the number of dimes is more than half the number of nickels,
then the dimes have more value.

-- If the number of nickels is more than double the number of dimes,
then the nickels have more value.

It is 198,87032,750 + 375 = 33145 so, we take the 6% and we make it a decimal (0.6) and multiply that, then that is your answer