5.8 Nickels
Step-by-step explanation:
Let x rep no of Nickels in Mike's cup
Then x - 0.2 = Number of quarters in Mike's cup
0.2x = Amount of money that mike has from the nickels
1 ( x - 0.2) = Amount of money that Mike has from the quarter
Then,
0.2x + 1 (x - 0.2) = 6
Expand the bracket
0.2x + x - 0.2x = 6
x = 6
Recall
x - 0.2 = 0
6 - 0.2 = 5.8
Therefore, Mike has 5.8 nickels for the quarter