Answer:
23
Step-by-step explanation:
The question gives the first equation:
0.05N + 0.10D = 2.20
It can be rewritten as:
0.05$ times the number of nickels plus 0.10$ times the number of dimes is equivalent to $2.20.
Notice that 0.05$ or 5 cents is equivalent to one nickel and 0.10$ or 10 cents is equivalent to one dime.
The question asks for N+D. We know that N stands for the number of nickels Daniel has and D stands for the number of dimes Daniel has. We also know that Daniel only has dimes and nickels in his pocket. Therefore N+D most be equivalent to the total number of coins, which is given in the question to be equal to 23 coins.
Therefore...
N+D = 23
