7. Marsha has three times as many quarters as she does nickels. She has a total of $3.20. How many of each coin does she have?
A. 2 quarters and 6 nickels
B. 12 quarters and 4 nickels
C. 8 quarters and 24 nickels
D. 18 quarters and 6 nickels

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950