Lets have the number of nickels be represented by x

Therefore,

Nickels = x(0.05)

Dimes = 2x(0.1)

Pennies = (2x + 9)(0.01)

Therefore, in an equation

x(0.05) + 2x(0.1) + (0.01)(2x + 9) = 3.60

0.05x + 0.2x + 0.02x + 0.09 = 3.60

0.27x = 3.51

x = 13

Therefore nickels = 13

Dimes = 2x = 2(13) = 26

Pennies = 2x + 9 = 2(13) = 9 = 26 + 9 = 35