Allison has $1.60 in nickels and dimes. She has 11 more nickels than dimes. How many dimes and nickels does she have?

0.05n + 0.10d = 1.60

n = d + 11

0.05 (d + 11) + 0.10d = 1.60

0.05d + 0.55 + 0.10d = 1.60

0.15d = 1.60 - 0.55

0.15d = 1.05

d = 1.05 / 0.15

d = 7 < = = = 7 dimes

n = d + 11

n = 7 + 11

n = 18 < = = = 18 nickels