Question
selecting three (3) coins, but assume that there are 5 dimes, 4 nickels, and 2 quarters.
In how many possible ways can the selection be made so that the value of the coins is at least 25 cents?
In how many possible ways can the selection be made so that the value of the coins is at least 25 cents?
Answers
Reiny
The only possible cases are, hope I did not miss any
DDD - 30
DDN - 25
DDQ - 45
DNN - 20
DNQ - 40
DQQ - 60
NNN - 15
NNQ - 35
NQQ - 55
How many of these amount to at least 25 cents?
(notice that the fact that we have 5 dimes and 4 nickels is of no consequence, since we can use at most 3, but the 2 quarters limits the cases)
DDD - 30
DDN - 25
DDQ - 45
DNN - 20
DNQ - 40
DQQ - 60
NNN - 15
NNQ - 35
NQQ - 55
How many of these amount to at least 25 cents?
(notice that the fact that we have 5 dimes and 4 nickels is of no consequence, since we can use at most 3, but the 2 quarters limits the cases)