Payment at tolls


#1

a lorry driver pays at all tolls, using only nickels and dimes, by throwing one coin at a time into the mechanical toll collector at tolls . In how many different ways can the driver pay a toll of 39 cents ?


#2

for information,
1 Nickel= 5 cents
1 Dime= 10 cents
so we can measure 40 cents in the following ways : -

  1. 8 nickels – 1 way
  2. 6 nickels 1 dime – if we arrange 6 nickels * N * N * N * N * N * N * in this way, then one dime can be placed in 7C1 ways
  3. 4 nickels 2 dime - 5C2 ways
  4. 2 nickels 3 dime- 3C3 ways
  5. 4 dimes- 1 way

therefore, total no. of ways= 1+7+10+1+1= 20