Skylar has 40% more pennies than nickels. If the value of Skylar's pennies and nickels is $2.56, how many nickels does Skylar have?
I couldn't figure out how to subtract 40%. 40% of what? of $2.56?
Call the number of nickels, x
Then....the number of pennies is 40% more = 1.4x
And the number of each * their denomination each gives us the total value.....so we have...
5x + 1 (1.4x) = 256 simplify
5x + 1.4x = 256
6.4x = 256 divide both sides by 6.4
x = 40 this is the number of nickels
And 1.4 (40) = 56 this is the number of pennies
Skylar has 40% more pennies than nickels. If the value of Skylar's pennies and nickels is $2.56, how many nickels does Skylar have?
p = pennies
n = nickels
Skylar has 40% more pennies than nickels:
p=n⋅(1+40 %)=n⋅(1+40100)=n⋅(1+0.4)=n⋅1.4p=1.4⋅n
The value of Skylar's pennies and nickels is $2.56:
p⋅1 Cent+n⋅5 Cent=256 Centp+5⋅n=256|p=1.4⋅n1.4⋅n+5⋅n=2566.4⋅n=256|:6.4n=2566.4n=40
Skylar does have 40 nickels.
pennies?
p=1.4⋅np=1.4⋅40p=56
and Skylar does have 56 pennies.