Serenity has some pennies and some nickels. She has no less than 18 coins worth at most $0.66 combined. If Serenity has 12 pennies, determine the maximum number of nickels that she could have. If there are no possible solutions, submit an empty answer.

10 nickels

Step-by-step explanation:

A pennie is a cent or $0.01. Serenity has 12 pennies so the amount she has from pennies is:

= 12 * 0.01

= $0.12

The amount she has in nickels at most is therefore:

= 0.66 - 0.12

= $0.54

A nickel is $0.05 so the number of nickels are:

= 0.54/0.05

=  10.8 nickels

= 10 nickels

If she has 10 nickels then the total she would have is:

= (12 * 0.01) + (10 * 0.05)

= $0.62

This fits the parameters

answer: i don't understand it

step-by-step explanation: sorry